DSpace Collection:
http://hdl.handle.net/2289/3429
Wed, 21 Apr 2021 05:34:28 GMT2021-04-21T05:34:28ZIridescent Crystals
http://hdl.handle.net/2289/7151
Title: Iridescent Crystals
Authors: Raman, C.V.; Krishnamurti, D.
Description: Open AccessMon, 01 Dec 1952 00:00:00 GMThttp://hdl.handle.net/2289/71511952-12-01T00:00:00ZThe correlated Hartree-Fock equations and the generalised density matrices
http://hdl.handle.net/2289/7123
Title: The correlated Hartree-Fock equations and the generalised density matrices
Authors: Viswanathan, K.S.
Abstract: The paper deals with a study of correlation effects in many-electron systems. Coulomb correlation is introduced into the theory by multiplying the Slater determinant formed from the one-electron orbitals by a correlation factor which is a symmetric and increasing function of the inter-electronic distances. The integro-differential equations satisfied by the best one-electron orbitals have been been deduced for non-stationary systems. From the extended Hartree-Fock equations given by Löwdin, the integro-differential equations satisfied by the density matrices have been derived. An expression for the energy-matrix of the system which is helpful in deriving a correlated Thomas-Fermi charge distribution, has also been given.
Description: Open AccessSat, 01 Apr 1961 00:00:00 GMThttp://hdl.handle.net/2289/71231961-04-01T00:00:00ZThe relativistic theory of chemical binding
http://hdl.handle.net/2289/7122
Title: The relativistic theory of chemical binding
Authors: Viswanathan, K.S.
Abstract: Starting from Breit’s relativistic equation for a system of two electrons, it is shown that for a hydrogen molecule (or for a system of two electrons moving in a field of cylindrical symmetry) the component of the total angular momentum (Jx) along the axis of the molecule (axis of symmetry) is a constant of motion. Thus every eigenstate of the system is simultaneously an eigenstate of Jx also, and a state of the system will specify, besides its energy, only the eigenvalue of the component of the angular momentum parallel to the axis of symmetry. The form of the four large components of the wave function relating to their dependence on the azimuthal co-ordinates has been given.
The case of Russel-Saunders approximation has been considered in detail and the nature of the components of the wave function for the singlet and triplet states has been discussed. It is shown that the wave function for the ground state of the hydrogen molecule could be expressed as a sum of a set of symmetric functions of which the first term is the Heitler-London function, and that the wave function for a triplet state should be a superposition of anti-symmetric molecular orbitals. It is shown that relativistic theory brings about in a natural manner the facts relating to the ground state of the molecules C2 and O2. Finally, some remarks are made concerning the case of molecules for which the spinorbit and the spin-spin couplings are strong.
Description: Open AccessWed, 01 Jul 1959 00:00:00 GMThttp://hdl.handle.net/2289/71221959-07-01T00:00:00ZOn the Pleochroism of Amethyst Quartz and its Absorption Spectra
http://hdl.handle.net/2289/7030
Title: On the Pleochroism of Amethyst Quartz and its Absorption Spectra
Authors: Pancharatnam, S.
Description: Open AccessFri, 01 Jan 1954 00:00:00 GMThttp://hdl.handle.net/2289/70301954-01-01T00:00:00Z