Nicholas Charles Handy (17 June 1941 – 2 October 2012) was a British theoretical chemist. He retired as Professor of
quantum chemistry
Quantum chemistry, also called molecular quantum mechanics, is a branch of physical chemistry focused on the application of quantum mechanics to chemical systems, particularly towards the quantum-mechanical calculation of electronic contributions ...
Samuel Francis Boys
Samuel Francis (Frank) Boys (20 December 1911 – 16 October 1972) was a British theoretical chemist.
Education
Boys was born in Pudsey, Yorkshire, England. He was educated at the Grammar School in Pudsey and then at Imperial College London ...
.
Research
Handy wrote 320 scientific papers published in
physical
Physical may refer to:
*Physical examination
In a physical examination, medical examination, or clinical examination, a medical practitioner examines a patient for any possible medical signs or symptoms of a medical condition. It generally co ...
and theoretical chemistry journals.
Handy developed several methods in quantum chemistry and theoretical
spectroscopy
Spectroscopy is the field of study that measures and interprets the electromagnetic spectra that result from the interaction between electromagnetic radiation and matter as a function of the wavelength or frequency of the radiation. Matter wa ...
. His contributions have helped greatly to the understanding of:
* the transcorrelated method
* the long range behaviour of Hartree–Fockorbitals
* semiclassical methods for vibrational energies
* the
variational method
The calculus of variations (or Variational Calculus) is a field of mathematical analysis that uses variations, which are small changes in functions
and functionals, to find maxima and minima of functionals: mappings from a set of functions t ...
for rovibrational wave-functions (in
normal mode
A normal mode of a dynamical system is a pattern of motion in which all parts of the system move sinusoidally with the same frequency and with a fixed phase relation. The free motion described by the normal modes takes place at fixed frequencies. ...
Slater determinant
In quantum mechanics, a Slater determinant is an expression that describes the wave function of a multi-fermionic system. It satisfies anti-symmetry requirements, and consequently the Pauli principle, by changing sign upon exchange of two electro ...
Anharmonic
In classical mechanics, anharmonicity is the deviation of a system from being a harmonic oscillator. An oscillator that is not oscillating in harmonic motion is known as an anharmonic oscillator where the system can be approximated to a ha ...
spectroscopic and thermodynamic properties using higher derivative methods
* Brueckner-doubles theory
* Open shellMøller–Plesset theory
* frequency-dependent properties
* Density functional theory : quadrature, new functionals and molecular properties.