Title 



A method for solving the molecular Schrödinger equation in Cartesian coordinates via angular momentum projection operators
 
Author 



 
Abstract 



A method for solving the Schrödinger equation of Natom molecules in 3N−3 Cartesian coordinates usually defined by Jacobi vectors is presented. The separation and conservation of the total angular momentum are obtained not by transforming the Hamiltonian in internal curvilinear coordinates but instead, by keeping the Cartesian formulation of the Hamiltonian operator and projecting the initial wavefunction onto the proper irreducible representation angular momentum subspace. The increased number of degrees of freedom from 3N−6 to 3N−3, compared to previous methods for solving the Schrödinger equation, is compensated by the simplicity of the kinetic energy operator and its finite difference representations which result in sparse Hamiltonian matrices. A parallel code in Fortran 95 has been developed and tested for model potentials of harmonic oscillators. Moreover, we compare data obtained for the threedimensional hydrogen molecule and the sixdimensional water molecule with results from the literature. The availability of large clusters of computers with hundreds of CPUs and GBytes of memory, as well as the rapid development of distributed (Grid) computing, make the proposed method, which is unequivocally highly demanding in memory and computer time, attractive for studying Quantum Molecular Dynamics.   
Language 



English
 
Source (journal) 



Computer physics communications.  Amsterdam  
Publication 



Amsterdam : 2009
 
ISSN 



00104655
 
Volume/pages 



180:11(2009), p. 20252033
 
ISI 



000273363700001
 
Full text (Publishers DOI) 


  
