A near linear-scaling smooth local coupled cluster algorithm for electronic structure.
We demonstrate near linear scaling of a new algorithm for computing smooth local coupled-cluster singles-doubles (LCCSD) correlation energies of quantum mechanical systems. The theory behind our approach has been described previously, [J. Subotnik and M. Head-Gordon, J. Chem. Phys. 123, 064108 (2005)], and requires appropriately multiplying standard iterative amplitude equations by a bump function, creating local amplitude equations (which are smooth according to the implicit function theorem). Here, we provide an example that this theory works in practice: we show that our algorithm leads to smooth potential energy surfaces and yields large computational savings. As an example, we apply our LCCSD approach to measure the post-MP2 correction to the energetic gap between two different alanine tetrapeptide conformations.
Subotnik
Joseph E
JE
Biophysics Program, University of California, Berkeley, California 94720, USA. subotnik@post.harvard.edu
Sodt
Alex
A
Head-Gordon
Martin
M
D000465:Algorithms; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003198:Computer Simulation; D008956:Models, Chemical