Calculation of the molecular integrals with the rangeseparated correlation factor
Abstract
Explicitly correlated quantum chemical calculations require calculations of five types of twoelectron integrals beyond the standard electron repulsion integrals. We present a novel scheme, which utilises general ideas of the McMurchieDavidson technique, to compute these integrals when the socalled "rangeseparated" correlation factor is used. This correlation factor combines the wellknown short range behaviour resulting from the electronic cusp condition, with the exact longrange asymptotics derived for the helium atom [Lesiuk, Jeziorski, and Moszynski, J. Chem. Phys. 139, 134102 (2013)]. Almost all steps of the presented procedure are formulated recursively, so that an efficient implementation and control of the precision are possible. Additionally, the present formulation is very flexible and general, and it allows for use of an arbitrary correlation factor in the electronic structure calculations with minor or no changes.
 Publication:

Journal of Chemical Physics
 Pub Date:
 March 2015
 DOI:
 10.1063/1.4915272
 arXiv:
 arXiv:1412.5070
 Bibcode:
 2015JChPh.142l4102S
 Keywords:

 Physics  Chemical Physics;
 Quantum Physics
 EPrint:
 published in J. Chem. Phys. 142, 124102 (2015)