Early ... Intro Picture

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                   Julg 1975                    Born in 1926. Studied at the École Normal Supérieur in Paris where he got his doctoral degree in 1955. After 2 years of prolonged stay at Paris he became Professor of Theoretical Chemistry at the University of Marseille from 1957-1986.
Julg died in Marseille in 2003.

Interview with Professor André Julg (in English)

Strasbourg, September 22, 1997; 14:00

Anders: Prof. Julg, you are, partly together with your wife, the author of a row of books (1-7 ), some of which were translated into foreign languages, and of some 150 articles (A1). In a case like France - where nearly everything that really happens is centered in and around Paris - it seems at first glance somewhat surprising that nearly all of your work originated from Marseille. How big was the University of Marseille around 1958? What was its standing in the French university ranking?

Julg & Wife in 1976

Professor Julg: At that time, there were only a few thousands of students in the Sciences. The arts people were at Aix-en-Provence {30 km north of Marseilles, I.'s n.}. The atmosphere was certainly pleasant, but the general level was not very high. Lower than in Paris. Moreover the University of Marseilles, unfortunately, had a rather bad reputation, like all the political institutions of the area. Yet one joked a little too easily on us you know, all the tall stories about Marseilles! In fact that always did not correspond to reality. There were nevertheless some good professors and some good students. But, once again, the average level was low. I knew all that, and if I went to Marseilles, it was for climatic reasons only.

A: Computers. There was no computer - - -

J: No. At the beginning, there was no computer at Marseilles. Thereafter, the problem got solved. We made calculations using a console with modem being connected to the center at Orsay, then at Montpellier.

In this context one should recall the role of the political intrigues in France concerning research. Toulouse and Marseilles disputed to have each a computing center. As there was no question of supplying each one of these cities a with a computing center, one built one halfway in between, at Montpellier. I also remind you of the of the discussion about the large particle accelerator for either Grenoble or Strasbourg. Here again politics played a vital role, without taking the scientific realities into account. Grenoble was finally selected because the municipality of Grenoble was at that time of the same colour as the government, which was not the case of Strasbourg.

A: How many students were there in theoretical chemistry at Marseilles?

J: Not many. I believe that the large majority of the students (and of the professors!) was not prepared for a teaching of Theoretical Chemistry. Moreover although I had the reputation of being a good professor, one found me too severe if not to say even too malicious.

Besides theoretical chemistry, I dealt with the candidates of the 'Contest of Aggregation' (in physics and in chemistry). It was a contest at the national level, therefore the Marseilles students were confronted with the candidates from all of France. It happened several times that one of my students obtained a first or second placement in this. In general they obtained a good ranking and consequently a good position in the secondary education, i.e. in the higher classes of the colleges (Preparation for the Ecole National Supérieur (ENS) and the Ecole Polytechnique). In addition, several of my researchers became professors or engineers. Others continued their career in research, like Bénard (8a) and Pellégatti (8b).

A: Pujol (8c-8dd)?

J: Pujol! After having become professor at the University of Marseilles (8d), he practically did not do any research. Each year he will do courses in Central Africa. He makes tourism and tennis!

A: And Bonnet (8e, 8ee)?

J: Bonnet? He went like Carles (8f, 8ff) into the pharmaceutical industry.

A: François (8g)?

J: He has switched into informatics, into pattern recognition. In this context he became interested in hieroglyphs.

A: Longuet-Higgins also went from theoretical chemistry into informatics - -

J: Informatics is not bad. Me, I have just a Macintosh to type my work. That is all I can do when I am in front of a computer, I cannot even calculate two plus two on it.

A: In fact the ideas are significant - -

J: It is true - -.

A: Where do you originate from?

J: Gegen 1650 kam mein Ur-Ur-Ur-Grossvater aus Baden-Württemberg ins Nord Elsass. Sein Name war Jüllg, vielleicht Jüllig, Jüllich - und von dort nach Marseille. Mein Grossvater ist in Marseille geboren. Mein Vater war natürlich auch Marseillaiser, meine Grossmutter kam von Genua. Die Mutter meiner Frau war von Mauersmünster, ihr Vater von Lièpre. Der Name Julg ist sehr selten. Ich habe einen Bruder, der war Deutschlehrer in Avignon. (Spoken in fairly flowing German by A. Julg himself; I' s. n.)

(It was about 1650 when my great - great - great - grandfather came from Baden-Württemberg, Germany into the neighboring northern Elsass and from there to Marseilles. His name was Jüllg, maybe Jüllig, Jüllich. My grandfather was born in Marseilles, my father as well. My grandmother came from Genua. The mother of my wife lived in Mauermünster (Elsass?). The name Julg is very seldom. I have a brother who taught German in Avignon.)

A: And then you went to the ENS in Paris - you must have been fairly good - - -

J: Yes, our son too. Louis de Broglie was my professor. . . (A2)

A: Another question on the side: I found a publication of Berthier with the participation Haïssinsky (9). Who was Haïssinsky?

J: A very picturesque and very nice character who worked at the Institut du Radium. He took the succession of Mrs. Joliot. You met Berthier (10)?

A: Yes. To me it appears that Berthier has been kind of a catalyst for theoretical chemists in France. Everybody remembers him.

J: Yes, Berthier is always very nice. Berthier was my master in theoretical chemistry. I had gone with a professor of the ENS to be introduced to Mr. and Mrs. Pullman, to start my diploma of higher studies. As they were to leave for six months for Israel - where one studied the thermochrome fulvenes experimentally - Mr. Pullman said to me: " We will be absent so here is Mr. Berthier, he will deal with you if you need help ". I had been attending the courses of de Broglie on quantum mechanics - but between general quantum mechanics and the application to theoretical chemistry there was a large difference! And that is how Berthier gave me the first elements of theoretical chemistry explaining to me in particular the method of Hückel. Since then we remained very connected.

A: In another interview Kutzelnigg (11) had also expressed a great appreciation for Berthier - -

J: He was several months at Berthier's.

A: Let's talk some more about you, how did you continue?

J: To return to my career, I told you that after my four years of ENS, I obtained in this institution a position of an "agregé preparateur" (of caiman in the slang of the school). It is a specific title of the ENS. That is the one who comes out first in the exams and who is entitled to this position. Pasteur had formerly occupied it. It was the equivalent to a master-assistant or to a lecturer as one says today. I had to occupy myself with the management of the chemistry laboratory as well as helping and advising the pupils of 3rd year in their preparations for chemistry. All that left me largely time to prepare my thesis.

After having finished my thesis in October 1955 (12), I remained for two more years as agregé preparateur. Yet actually I wanted to go back to Marseilles. On one hand I was not married and on the other hand the northern climate was not appropriate for me {Julg had been struck by poliomelythis when he was a child I'.s n.}. Too much cold, too much rain and snow. In October 1957 a chair of theoretical chemistry was created for me. The first one had gone to Barriol (13) in Nancy, the third one would later go to Mr. Pullman in Paris. Coming to Marseilles as professor, my career was ensured, financially at least. But I knew that I did not have as many possibilities to work nor as many students and good researchers than if I had remained in Paris. I would have launched out into large calculations without reflecting. I would certainly have found interesting things to do but I would not have had new ideas.

Often one is astonished that it is in the poor countries that one has the most ideas. Of course! Deprived of monetary means, it only remains for them to reflect. In any case, this orientation towards reflection corresponded completely to my character. As a child I already had dreamed to write a large book of synthesis which would relate to all sciences. Besides theoretical chemistry mineralogy and palaeontology always had interested me. I have in Marseilles a large collection of fossils and minerals. Astronomy and cosmology impassion me too. All this interests me because it forms a part of a completeness in which all is contained (7). I have the mind of a theoretician who would like to know all for a better understanding of the beauty of our universe. Naturally, I published many applications of the theory, in particular on the structure and the properties of the conjugated molecules (14). I was interested in the color of the minerals (15). My last article studies the origin of the green color of the amazonite, a semi-precious stone of Madagascar. It is a micro cline feldspar whose color arises through the ions Pb+ and Pb3+, not Pb2+ (16)!

However, since I am in retirement it is the interpretation of the quantum mechanics which occupies me most strongly (7).

J: {spoken in English by A. Julg himself; I's. n.} "My idea is the following : No system in the universe is strictly isolated but it is intrinsically exchanging energy with other systems in the universe. And the study of atoms and molecules arises from the bonds between the radiative power of the atom in requiring the energy from the rest of the universe. It is possible to find again a quantum formalism to explain quantum phenomena for instance the tunnel effect, the spin etc. by a strictly classical interpretation".

A: In some of your papers (17) you use the French term physique sous-jacente. What does the French term signify, what do you mean by this?

J: {Julg in English, I.'s n.} Underlying. In my interpretation a difficulty appears with respect to the traditional interpretation - the energy is not rigorously constant. But this difficulty is removed by the symmetrization of the operators.

J: {continues in French} I wrote a book which exposes my thesis (7) but I always change chapters, improving it each time. It is very difficult to find an editor for it. Very difficult because one publisher said to me "it will not sell". Hadronic Press said to me: "One will sell 30 in the United States". And then, you see, there are many people who use theoretical chemistry in the same manner as I use the car : it runs, I do not want to know why. This is what theoretical chemistry is for some: only a working tool, I accept it. Of course I do not call these people 'theoreticians'. They are nothing else but users. Exactly as one uses a mass spectrometer or a particle accelerator. And for all that is to say, it is that what very early separated me from the Pullman Laboratory, Mr. Pullman especially, who was not interested in the theory as such, much less than Mrs. Pullman.

J: Did you know Claverie? He died very young, he was somebody very remarkable. He was a researcher of the theory, he made applications and he was interested in the theory. He was particularly interested in stochastic electrodynamics (18).

A: Like you?

J: No, not particularly in stochastic theory. It is our son who gave the first example - he was very young, 18 years ago - that stochastic electrodynamics does not work in certain cases. He was the first to find a discrepancy for the anharmonic oscillator (19a).

A: Where did Clavery work?

J: At Pullman's. Only, Pullman had given him a research topic which was way out from what Claverie was interested in, namely the interpretation of quantum mechanics. But Mr. Pullman never believed in the work of Claverie. That did not interest him. Daudel on the other hand was more interested.

A: Daudel is a very interesting character (20) - -

J: Yes - - it has been years that I know Daudel. You knew Mrs. Daudel?

A: No. By the way, was Mrs. Daudel his former student Pascaline Salzedo? There once was joined publication with Daudel (21).

J: Right, the future Mrs. Daudel.

A: And how was the situation between Pascaline Salzedo and Alberte Bucher (22a-b)?

J: Ah, yes, there were problems - - well, between Daudel and Pullman, of course - - .Daudel has had a bad policy at the beginning to accept too many people. He recruited people who perhaps were not at level. On the other hand, Pullman never had at first but one pupil - that was Berthier. Then he accepted me to do my thesis but I was not permanently in the laboratory because I was at the ENS.

And then he has had also Mrs. Josianne Serre. Her husband is Jean-Pierre Serre, winner of the Fields Medal of Mathematics. Mrs. Serre later left the ENS. By the way, Mrs. Serre began her thesis the same day as me. Having entered three years before me into the ENS, she had started with a thesis on peroxides. But then she had a very serious accident. Not wanting anymore to continue experimentally, she asked me to present her to Pullman. And Pullman accepted her. Her thesis related to the acetylenes (23). Thereafter she became director of the ENS for girls. She had too much administrative work and did no longer do any theoretical work.

That is regrettable because she had started to introduce, following certain ideas of her husband, the theory of the groups in theoretical chemistry. She had even found something very remarkable. If one takes into account the cores and the electrons of a certain molecule one finds that all of the coordinates of these particles were invariant under rotation meaning that the molecule would be spherical! For a trained chemist like her this was shocking. Also, in spite of its confidence in the theory of the groups, she did not publish this result. The Englishman Woolley re-found it somewhat later and published it (24a-b). That is what I called the paradox of Woolley. Although paradox in an orthodox theory, this proposal is explained simply in my interpretation of quantum mechanics.

For me, quantum mechanics gives only the average value

of the various sizes over a sufficiently long period. In

the average, at the end of an extremely long but closed time

segment, one must observe the isotropy for all molecules.

I will give you another example of the role of the factor 'time' on the result of observations. It is that of the optical inverse molecules. One can separate the right arsines from the left arsines, but not the amines (25). Or qualitatively, the problem is the same one, that of an apical core (these molecules are pyramidal) which oscillates in a double well of symmetrical potential. The wave function has two maxima corresponding respectively to the right form and the left form. The wave function thus describes the totality of the two forms, deprived of optical activity. The difference between the amines and the arsines arises from the fact that the oscillation in the amines is too fast to be detected whereas it is slow (with a period of one year) for the arsines. One observes the quantum forecast for the amines by means of only one experiment, whereas for the arsines it is necessary to make the average over several years (26). It is a good argument for my interpretation which I call quasi-ergodic (7).

A: Is this idea accepted?

J: Is this idea accepted??!! It is a fact that it is very difficult if not often impossible to publish it. At the time of a congress in Uppsala, a referee spoke about the "mystery of the arsines"! But it was a physicist who did not know anything about chemistry!

Now I show to you something else {presents a huge hand-written piece of paper, about 1 X 1.5 meters; I.'s.n.}. I had said to you that I had studied azulene (27) in my thesis (12). Here I want to show you an example of a calculation (A3) and the molecular Coulomb integrals between an asymmetrical state and a symmetrical state in order to calculate the transition energy.

Here is how I worked. I will explain it to you : Here you have the atoms with the orbital coefficients. I then took then the product of the coefficients. Then I wrote in blue products of 4 coefficients, in red I wrote the product of the corresponding integral (pq, rs) . Finally I added all the terms.

A: And not one error?

J: No, No, No - - none, none!! And I found for the first time, as I explained to you, the exact charges in azulene. One or two years after these calculations I received a letter of Bernstein and Schneider, Canadians, who worked in magnetic nuclear resonance (28). They had shown that my charges were good. Unfortunately I lost the letter. That gave me the pleasure, two years later, to see that my thesis had correct forecasts. Parr had been very impressed by this table.

There is something which I did not tell in a my 'A Page of history: Improved method L.C.A.O. (29). When I did my calculations on azulene, as I explained to you, I suddenly encountered divergence! And I battled, during two or three months, without having convergence. Mr. Pullman, a little sympathizing, said to me: "You made an error in your calculation." Whereas I knew that I had not been mistaken. Mr. Pullman asked his calculating woman, Mrs. Baudet (30a-e), to check my last calculation. It turned out to be correct. Then I reflected and found the mathematical solution. The theory is a little complex, its exposition here would not add anything to the history. I would say simply that the convergence or the divergence of certain successions of terms is connected to the existence of imaginary roots of a certain equation. In the case of fulvene studied by Berthier, there was convergence (31a-b). In azulene there was divergence because the equation had imaginary roots. The same applies to heptafulvene (32).

An amusing story on the side : While I did this work Pullman was travelling in the USA, met Parr there who had the same difficulties with azulene. Without insisting too much, Pullman mentioned to Parr that he had a student who ran up against the same problem. Parr had at its disposal a computer program which accelerated the convergence in the atoms (he set out each time again from the half sum of the values obtained from the preceding two iterations). But that did not work, there was always divergence. Finally, I had arrived at the result before Parr because I did not have a computer! Man ranks higher than the machine! But when I reflect, it is fortunate that Berthier did n ot encounter problems, without that I would never have attacked azulene by the SCF method.

A: Was it necessary to orthogonalize orbitals? Who first had the idea of doing the orthogonalization of the orbitals?

J: Mathematically, it is not necessary to use orthogonal orbitals, but calculations are shorter and more rapid. The author who first introduced the use of orthogonal orbitals, was Landshoff (33).

A: Landshoff, not Löwdin?

J: Landshoff, he was the first (33)! Landshoff, he was a the one who had studied the sodium chloride crystal. For his crystal orbital he had imagined to orthogonalize them. And he orthogonalized them to the first term only. He had started this development! He did not work on the whole matrix of the exchange(??) integrals, he had made a limited development. Löwdin used the complete development. He as well applied it initially to crystals only, and not to molecules as such (34a-b). But in the end the idea was of Landshoff! You can find the reference to Landshoff in the SCI (Scientific Citation Index). It is there where he explained the process (35).

A: You worked in a variety of fairly different fields - -

J: You perhaps found my article on the hardness of the minerals (6)? When I obtained this formula (6; p.50), the referee had told me: "Yes, I agree. But how did you find the formula? " - "Ah - - " I said "ah - -! " How had I found it??!! I did find it - and it works very well!

A: It is really interesting to see how you widened and deepened your thinking - starting from 'ordinary' quantum chemistry - -

J: "... the ideas often come to me while walking ... " had said Dirac. This applies to me as well. Often while driving or suddenly without apparent reason. Did I send you my article hybridization?



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{ Looking further through has list of publications. I.'s notes }. It is in a special number of Theochem on the occasion of the 75th anniversary of Linus Pauling where I explain how the hybridization of an orbital corresponds to a physical reality (36). This history of fluctuations of the density is explained in an article which I did together with our son Pierre. Here it is : A. Julg and P. Julg (19b) where I explain that the chemical bond corresponds to regions in which the electrons remain for a certain time, and which one can call the 'orbital regions' with a minimal fluctuation. It is a concept which exceeds those of the 'loges' of Daudel (37a-e). Because the loges of Daudel work, correctly in certain cases, but when you have free electron pairs, the partition of space into loges is no longer possible. The loges of Daudel correspond to the chemical bond if you have molecules like methane but for ammonia there are no more loges of minimal fluctuation (A4). On the other hand there are always orbital regions, but they are not regions of the geometrical space. One has to use a more abstract space.

Hybridization allows to find regions of minimal fluctuation directly. It thus makes physical sense, corresponding approximately to the electron pairs of Lewis. In my ergodic concept of quantum mechanics, the electrons spend a certain time in each region (i.e. each localised bond) before exchanging between the two of them. So that, on the average, they have in the end all the same properties, which is not the case in the traditional description.

Another example which illustrates the phenomenon of exchange between the electrons is that of Slater's rules. These rules make it possible to determine Z of a certain atomic orbital. They classify the electrons into inner and outer electrons. The charges of the inner electrons shield the considered electron from the nucleus and those of the outer electrons have no effect. However this is contrary to the equivalence of electrons. There are neither 'inner' nor 'outer' electrons. The difficulty is overcome if one says that during a certain time an electron is on an inner orbital, then on an outer orbital. Thus, at every moment there are as many inner electrons as outer electrons, but they exchange their places in the course of time. It is for this reason that carbon binds to 4 hydrogen atoms to give CH4 and not with six although it has 6 electrons. Because the inner electrons are less accessible against the four outer ones, being thus more available geometrically.

A: One more question concerning Daudel : Daudel maintained in my interview with him (20) that Bader (38a-c) continued to uses his (Daudel's) idea about the loges. However, looking at Bader's work I find only very few, if any, mention towards Daudel and the loges - -

J: It is true. The idea of Bader was to check if the virial theorem would apply to the loges (38c). Indeed, when the loge exists, the two electrons which occupy it verify the virial theorem. That means that such loges make physical sense - but only when they exist - which, as I said to you - is not always the case. Bonding within the meaning of Lewis thus does not correspond to the loges of Daudel or Bader.

A: Coming back to your ideas. How are they viewed nowadays?

J: An example of the difficulties which I encountered with my not very orthodox ideas on quantum mechanics : I had presented, a few years ago, to an international conference of chemistry in Montreal a poster on the symmetrization of the quantum operators and shown that the essential consequence to know is that energy fluctuates. The reaction of people was rather hostile since for them energy did not fluctuate. Admittedly some intelligent people were interested. How was the name of this German who paid attention there? Schwarz! When I wanted to publish my work in the acts with the conference, it was refused. Reason of the referee: "It was the year of the centennial of the birth of Bohr! And then, with respect to his memory, one cannot publish an article saying that energy fluctuated."

A: Scientific politics - -

J: Exactly! It was the centennial of Bohr! What do you believe I did? To publish the article when there wasn't the centennial any longer? I nevertheless had trouble getting this article accepted. It was for the 65th anniversary of our friend Koutecky (39).

Now, about this article which I had sent to Theoretica Chimica Acta, at that time edited by Ruedenberg. Very friendly, Ruedenberg, told me the following story. He had successively sent it to five referees which all refused it. However Ruedenberg thought that it contained nevertheless something important. It so happened that he met an old quantum chemist, who said to him: "That is very interesting because those were problems which Dirac himself had approached without solving them". I do not know if you read the book of Dirac of 1930 (xx). Dirac explains why the operators do not always correspond to physical reality and that sometimes corrective constant terms have to be added, in particular to the operators. But precisely these consequences were horrible and consequently no one liked to even mention it! But this old quantum chemist knew the problem and said to Ruedenberg: "It is very interesting, I vote for this article." But Ruedenberg changed a little the title into - -

A: New Thoughts on an Old Problem - -

J: Ah, here (39). He told it to me later, one day when we met on occasion, it was funny. The conclusion is that the young people did not read the passage, did not know the construction of quantum mechanics. What they now get presented are completed entities. If they would have looked at papers of the old authors - who are called 'the founder figures' - they would not have been so affirmative. Me, I had followed the courses of Louis de Broglie at the ENS. And one understood from his explanations that he himself was not so sure about it, he did not claim to have the truth. He said: "It is complicated". Because he it had lived it, he understood it. For the young people, once past their examinations, and when there are no more problems, all is finished for them. And if you discuss other things in addition to this, it disturbs these young people, that does no longer interest them.

And in this sense my theory disturbs. I had the occasion to meet Dirac. That was back in 1952. He was in Paris to hold a conference on quantum electrodynamics. I was there for a few days as well due to a 'contest of aggregation' {as explained above I.'s n.} but I had nevertheless gone to see the appearance of Dirac. He was a very picturesque character. The conference was at the Institut Poincaré. There was large board, about 7 meters long! Dirac wrote very quickly. He spoke a very pleasant French, but I did not understand much of his talk, it was too complicated. Suddenly somebody raised his hand and said : "Sir, there is an error of sign." Then Dirac answered : "It is possible!", he corrected the sign and continued. That impressed me very much! He was somebody of the higher class, Dirac. His book 'Principles of Quantum Mechanics' is a monument (40).

A: Even nowadays people admires his work - e.g. in modern quantum optics - -

J: But there are other basic works. The book of Pauling and Wilson 'Introduction to Quantum Mechanics' is very interesting (41). There is also Eyring, Walter and Kimball 'Quantum Chemistry' (42). As well as the book of Pullman 'Les théories électroniques de la Chimie Organique' (43). These books have disappeared. They all were very interesting. It would be necessary that the young people read them!

A: Professor Julg, I thank you very much for this detailed interview.





References and Notes

(1) A. Julg, Chimie Quantique, 2nd. Dunod, Paris, 1967.

(2) A. Julg, O. Julg, Exercices de chimie Quantique. Dunod, Paris, 1967.

(3) A. Julg, Atomes et liaisons. Colin, Paris, 1970.

(4) A. Julg, Chimie Quantique structurale et éléments de spectroscopie théorique.

Office des Publications universitaires, Alger, 1978.

(5) A. Julg, La liaison chimique. Presses Universitaires de France, Paris, 1980.

(6) A. Julg, Crystals as Giant Molecules. Springer, Berlin, 1984.

(7) A. Julg, From Atoms and Molecules to the Cosmos. A Quasi-Ergodic Interpretation

of Quantum Mechanics. Springer, Berlin, 1998.

(8a) A. Julg, M. Bénard, Un procédé général de traitement des molécules conjuguées.

La méthode LCAO améliorée avec interaction vibronique

(Application aux hydrocarbures).

Tetrahedron 24, 5575-5585 (1968) and later publications.

(8b) A. Julg, A. Pellégatti, Recherches théoriques sur la structure électronique de molé-

cules contenant des atomes hydridées en sp.

Theor. Chim. Acta 2, 202-209 (1964) and later publications.

(8c) L. Pujol, A. Julg, Structure électronique du furanne. Méthode L.C.A.O. améliorée.

Theor. Chim. Acta 2, 125-133 (1964) and later publications.

(8d) G. Pouzard, L.Pujol, Energie des systèmes H2, HHe+ et LiH* .

Theor. Chim. Acta 26, 187-193 (1976)

(8dd) M. Carles, D. Eloy, L. Pujol, H. Bodot, Photochromic and thermochromic .

salicyliden amines .....

J. Mol. Struct. 156, 43-58 (1987).

(8e) A. Julg, M. Bonnet, Traitement L.C.A.O. amélioré des molécules conjugées.

II. - Application aux molécules contenant des hétéroatomes.

J. Chim. Phys. 57, 434-438 (1960) and later publications.

(8ee) M. Bonnet, A. Julg, J.F. Queffelec, J.C. Tardy, Tables d'intégrales moléculaires.

Tome 1 + 2. Ed du CNRS, Paris, 1968.

Cited from: Y. Ozias, L. Reynard, Theor. Chim. Acta 20, 56 (1971).

(8f) A. Julg, P. Carles, Étude de la conjugaison du doublet électronique de l'azote avec

un système insaturé (Méthode L.C.A.O. améliorée).

J. Chim. Phys. 59, 852-855 (1962) and later publications.

(8ff) P. Carles, Thèse. Marseille, 1968.

(8g) A. Julg, P.Francois, Structure électronique de l'hexatriène (Méthode L.C.A.O.

améliorée). J. Chim. Phys. 57, 63 (1960) and later publications.

(9) The question concerning Haissinsky was put here since this person has had some significance in the Pullman

interview as well. I considered it worthwile to add the question at this moment, although realizing it being somewhat

out of context in the present interview. See also:

G. Berthier, Problèmes théoriques liés à la détermination des coefficients d'auto-

diffusion dans les solides pas la méthode des échanges isotopiques

hétérogènes. J. Chim Phys. 49, 527-536 (1952).

This article finishes with "Je remercie égalment M. Haissinsky qui m'a suggéré d'entreprendre ce

travail et m'a apporté constamment ses encouragements et conseils."

(10) See: Interview with G. Berthier, Paris, June 2, 1997.

(11) See: Interview with W. Kutzelnigg, Bochum, July 24, 1997.

(12) A. Julg, Thèse. Paris, 1955.

(13) On some more details about Barriol see also reference (10).

There are several books by Barriol; his maybe best-known book is:

J. Barriol, Elements of Quantum Mechanics with Chemical Applications.

Barnes and Noble, New York, 1971.

The original: Éléments de Méchanique Quantique. Masson, Paris, 1966.

(14) This covers especially the early publications from 1953 to about 1971, altogether

some 60 publications on this topic. The corner stones of the LCAO améliorée

method were laid in:

A. Julg et al., J. Chim Phys. 57, 19, 63, 434, 490, 597 (1960).

A. Julg, Un perfectionnement de la théorie des orbitales moléculaires:

La méthode L.C.A.O. améliorée.

Tetrahedron 19, Supplement 2, 25-41 (1963).

See also:

A. Julg: The Little Story of the LCAO Improved Method, Marseille, 1997,

following this interview where A. Julg tells the story of his method in his

own words.

(15a) A. Julg, La couleur des minéraux. Relation avec la strucutre et la composition

chimique. Sa prévision théorique.

Folia Chimica Theoretica Latina (FCTL), XVII, 93 (1989).

(15b) A. Julg, O. Julg, Sperical box model and reduction of coulomb interactions in the

crystal field theory of 3dn ions. Can. J. Chem. 63, 1955 (1985).

(15c) A. Julg, M. Fernandez-Nuñez, A theoretical study of the spectrum of 3dn adsorbed

on ionic crystals: Co2+ on calcute and aragonite.

J. Mol. Struct. (Theochem) 254, 301 (1992).

(16) A. Julg, A theoretical study of the absorption spectra of Pb+ and Pb2+ in site K+

of microline: application to the color of amazonite.

Phys. Chem. Minerals 25, 229 (1998).

(17) A. Julg, Le mythe des orbitales moléculaires.

Bull. Soc. Chim. Belg., 85, 985-993 (1976).

(18) e.g. P. Claverie, Discussion of Claverie and Diner's Paper: The Classical Limit in

the Framework of Stochastic Mechanics.

In O. Chalvet et al (eds.), Localization and Delocalization in

Quantum Chemistry, Vol II, p 449-460. Reidel Publishing Co.,

Dordrecht-Holland (1976).

(19a) P. Julg, L'électrodynamique stochastique.

Folia Chimica Theoretica Latina, VI, 99 (1978).

(19b) A. Julg, P. Julg, Vers une Nouvelle Interprétation de la Liaison Chimique.

Int. J. Quant. Chem. 13, 483-497 (1978).

(20) See: Interview with R. Daudel, Paris, June 3, 1997.

(21a) R. Daudel, Pascaline Salzedo, A propos de la variation de la covalaffinité d'un

élément avec sa valence.

Comptes Rend. 218, 972-973 (1944).

(21b) Pascaline Daudel, Sur la méthode des diagrammes moléculaires.

Comptes Rend. 223, 947-948 (1946).

(22a) Alberte Bucher, married Mrs. A. Pullman, initially started work with R. Daudel:

(22b) R. Daudel, A. Bucher, H. Moureu, Une nouvelle méthode d'étude des valences

dirigées. Son application à la détermination de la structure

des penta-halogénures de phosphore.

Comptes Rend. 218, 917-918 (1944).

(23) J. Serre and A. Pullman, Recherches théoriques sur les composés acétyléniques.

I. Structure électronique de l'acétylène.

J. Chim. Phys., 50, 445-458 (1953).

(24a) R.G. Woolley, Quantum Theory and Molecular Structure.

Adv. Phys. 25, 27-52 (1976).

(24b) R.G. Woolley, Must a Molecule have a Shape?

J. Amer. Chem. Soc. 100, 1073-1078 (1978).

(25) A. Julg, Une nouvelle approche de la notion de mesure en mécanique quantique.

Fol. Chim. Theo. Latin. (FCTL) 19, 73-84 (1991).

(26) A. Julg, The problem of enantiomers: Support for a new interpretation of quantum

mechanics.. Croat. Chim. Acta 57, 1497 (1984).

(27) A. Julg, Étude de l'azulène par la méthode du champ moléculaire self-consistant.

J. Chim. Phys. 52, 377-381 (1955).

(28) Schneider, Bernstein Pople : NMR

(29) See: A. Julg: The Little Story of the LCAO Improved Method, Marseille, 1997,

following this interview where A. Julg tells the story of his method in

his own words.

(30a) J. Baudet was the former J. Pontis, who had published with A. Pullman. See also:

Interview with A. Pullman, Paris, 1997. J. Baudet was named assistant to B. Pullman when he became professor

at the Sorbonne. J. Baudet remained his assistant for many years.

(30b) A. Pullman, B. Pullman, E.D. Bergmann, G. Berthier and J. Pontis,

Fulvènes et éthylènes thermochromes.

10e. Recherches sur les naphtofulvènes.

Bull. Soc Chim. France, 1951, 681-685.

(30c) also e.g.: G. Berthier, B. Pullman and J. Pontis, Recherches théoriques sur les

constantes de force et les fréquences de vibration du

groupement carbonyle dans les molécules organiques

conjugées. J. Chim. Phys., 49, 367-376 (1952).

(30d) also e.g.: , B. Pullman, A. Pullman, G. Berthier and J. Pontis, Les pléiadiènes.

J. Chim. Phys., 49, 20-23 (1952).

(30e) A later publication when J Pontis was married to Baudet (During that time, J. Baudet,

according to A. Pullman, served as a university assitant to B. Pullman):

J. Baudet, G. Berthier and B. Pullman, Sur la fréquence de vibration du groupement

carbonyle dans les quinones polycycliques.

J. Chim. Phys., 54, 282-284 (1957).

(31a) G. Berthier, LCAO Self-Consistent Field Calculations of the pi-Electrons Energy

Levels and Electronic Structure of Fulvene.

J. Chem. Phys. 21, 953-954 (1953).

(31b) G. Berthier, Structure électronique du fulvène: Étude par la méthode di champ

moléculaire self-consistent. J. Chim. Phys. 50, 344-351 (1953).

(32) A. Julg, Structure électronique de l'heptafulvène. Étude par la méthode du champ

moléculaire self-consistent. J. Chim. Phys. 52, 50-52 (1955).

(33) R. Landshoff, Quantenmechanische Berechnung des Verlaufes der Gitterenergie

des Na-Cl-Gitters in Abhängigkeit vom Gitterabstand.

Z. Phys. 102, 201-228 (1936).

(34a) P.O. Löwdin, On the non-orthogonality problem connected with the use of

atomic wave functions in the theory of molecules and crystals.

J. Chem. Phys. 18, 365-375 (1950).

(34b) P.O. Löwdin, On the quantum mechanical calculation of cohesive energy of

molecules and crystals.I. A general energy formula for the ground

state. J. Chem. Phys. 19, 1579-1591 (1951).

(35) A. Julg. The priority question has always been discussed by Julg in this sense;

see e.g. reference (1), p. 103.

(36a-c) A. Julg, Is hybridization just an artefact or does it reflect some physical

reality? J. Mol. Struct. (Theochem) 169, 125 (1988).

(36d) A. Julg, Quelques réflexions sur la notion de molécule et leurs implications

concernant l'interprétation de la mécanique quantique.

Folia Chimica Theoretica Latina (FCTL), 21, 205-213 (1993).

(37a) R. Daudel, S. Odiot, H. Brion, Théorie de la localisabilité des corpuscules.

I: La notion de loge et la signification géométrique de la

notion de couche dans le cortège électronique des atomes.

J. Chim. Phys. 51, 74-77 (1954).

(37b) H. Brion, R. Daudel, S. Odiot, Théorie de la localisabilité des corpuscules.

II: Niveaux électroniques des atomes et énergies associées

aux loges.

J. Chim. Phys. 51, 358-360 (1954).

(37c) S. Odiot, R. Daudel, Théorie de la localisabilité des corpuscules.

III: Retour sur la signification géométrique de la notion de


J. Chem. Phys. 51, 361-362 (1954).

(37d) R. Daudel, H. Brion, S. Odiot, Localizability of Electrons in Atoms and Molecules

Application to the study of the notion of shell and

of the Nature of Chemical Bonds

J. Chem. Phys. 23, 2080-2083 (1955).

(37e) R. Daudel, Fundamentals of Theoretical Chemistry.

Pergamon Press, Oxford, 1984.

(38a) R.F.W. Bader, An Introduction to the Electronic Structure of Atoms and

Molecules. Clarke, Irwin & Co., Toronto, 1970.

(38b) R.F.W. Bader, Atoms in Molecules. Clarendon Press, Oxford, 1990.

(38c) R.F.W. Bader, Comparison of Loge and Virial Methods of Partinioning

Molecular charge distrinutions. In O. Chalvet et al (eds.),

Localization and Delocalization in Quantum Chemistry.

Vol I, 15-38. Reidel Publishing Co., Dordrecht-Holland (1975).

(39) A. Julg, From Atom to Cosmos.

J. Molec. Struct. (THEOCHEM) 166, 33-38 (1988).

(40) P.A.M. Dirac, The Principles of Quantum Mechanics. 4th ed.

Clarendon Press, Oxford, 1958.

(41) L. Pauling, E.B. Wilson, Introduction to Quantum Mechanics.

McGraw-Hill, New York, 1935.

(42) H. Eyring, J. Walter and G.E. Kimball, Quantum Chemistry.

John Wiley, New York, 1944.

(43) B. Pullman, A. Pullman, Les théories électroniques de la chimie organique.

Masson, Paris, 1952.

(44) In bringing this text from audio tape to paper the interviewer gratefully acknowledges for some parts the help of

Mrs. Lydia Hegedüs und Mr. and Mrs. Cataldo.

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