Peter J. Knowles

An efficient internally contracted multiconfiguration–reference configuration interaction method

A new internally contracted direct multiconfiguration–reference configuration interaction (MRCI) method is described which allows the use of much larger reference spaces than an...

A second order multiconfiguration SCF procedure with optimum convergence

An MCSCF procedure is described which is based on the direct minimization of an approximate energy expression which is periodic and correct to second order in the changes in the...

An efficient method for the evaluation of coupling coefficients in configuration interaction calculations

An efficient second-order MC SCF method for long configuration expansions

Accurate multireference configuration interaction calculations of the potential energy function and the dissociation energy of N2

The potential energy function of the N2 molecule is calculated using the internally contracted multireference CI method (CMRCI) and complete active space SCF (CASSCF) reference ...

<i>A</i> <i>b</i> <i>i</i> <i>n</i> <i>i</i> <i>t</i> <i>i</i> <i>o</i> calculations on the four lowest electronic states of AlF+ and AlCl+

The potential energy curves of the two lowest 2Σ+ (X,B) and the two lowest 2Π (A,C) electronic states of the AlF+ and AlCl+ molecular ions have been calculated using highly corr...

Fast linear scaling second-order Møller-Plesset perturbation theory (MP2) using local and density fitting approximations

We apply density fitting approximations to generate the 2-electron integrals in local MP2 (LMP2) to produce a method denoted DF-LMP2. The method can equally be seen as a local v...