# Au-Chin Tang

Born November 18, 1915 in Yixing, Jiangsu Province, China. Professor of Jilin University, Changchun, PR of China.

Honorary Chairman of the National Natural Science Foundation of China. Honorary President of Jilin University. Honorary Director, the Institute of Theoretical Chemistry, Jilin University. Honorary Doctor of Law, Windsor University, Canada. Honorary Professor, Rutgers University, USA. Won four National Natural Science Prizes (Third class in 1956, Second Class in 1989, and First Class in 1982 and 1987).

## Author of:

Theoretical Method of Ligand Field Theory. Graph Theoretical Molecular Orbitals. Quantum Chemistry. Statistical Theory on Polymeric Reactions. Applied Quantum Chemistry. Introduction to Irreducible Density Matrics. Dynamics of Molecular Reactions. Supplement to Theoretical Method of Ligand Field Theory - the V-Coupling Coefficients from SO(3) to the point Groups. Over 200 articles in various books and journals.

## Important Contributions:

In the fifties, Professor Tang Au-chin proposed a new method for computing the potential function of molecular internal rotation and applied it to analyzing the potential functions of nearly 100 molecules with satisfactory results, and then won the Third Class of National Natural Science Prize of China (NNSPC) in 1956.

In the sixties, he introduced the coupling coefficients from the three-dimensional rotation group to the point group and developed the irreducible tensor method from the continuous groups to the point groups in the ligand field theory, then won the First Class of NNSPC in 1982.

In the seventies, he established three foundational graph theorems in Hückel approximation on the characteristic polynomials and their symmetrical reduction, intrinsic vectors, energy level of the conjugated molecules, then won the First Class of NNSPC in 1987.

While he has been working in the field of statistical theory of polymer reactions for more than thirty years, he firstly obtained the molecular weight distribution function of addition polymers, and predicted the gel points and sol-gel distribution after gelation of many complicated reaction systems from his curing theory, then won the Second Class NNSPC in 1989.

Recently he has worked on the structure rule of cluster compounds, curing theory and scaling study of polymers and obtained significant results.

An obituary can be found at

1.

**http://www.iaqms.org/obituary/Au-ChinTang.pdf**.

2.

**http://link.springer.com/article/10.1007%2Fs11426-008-0147-8**.