Low-rank sum-of-products finite-basis-representation (SOP-FBR) of potential energy surfaces

2020 ◽  
Vol 153 (23) ◽  
pp. 234110
Author(s):  
Ramón L. Panadés-Barrueta ◽  
Daniel Peláez
2017 ◽  
Vol 16 (05) ◽  
pp. 1730001 ◽  
Author(s):  
Alex Brown ◽  
E. Pradhan

In this paper, the use of the neural network (NN) method with exponential neurons for directly fitting ab initio data to generate potential energy surfaces (PESs) in sum-of-product form will be discussed. The utility of the approach will be highlighted using fits of CS2, HFCO, and HONO ground state PESs based upon high-level ab initio data. Using a generic interface between the neural network PES fitting, which is performed in MATLAB, and the Heidelberg multi-configuration time-dependent Hartree (MCTDH) software package, the PESs have been tested via comparison of vibrational energies to experimental measurements. The review demonstrates the potential of the PES fitting method, combined with MCTDH, to tackle high-dimensional quantum dynamics problems.


2017 ◽  
Vol 19 (33) ◽  
pp. 22272-22281 ◽  
Author(s):  
Ekadashi Pradhan ◽  
Alex Brown

Using CCSD(T)-F12/cc-pVTZ-F12 and CCSD(T)/CBS ab initio energies, two different six-dimensional ground state potential energy surfaces for HONO have been fit in sum-of-products form using neural network exponential fitting functions and tested by computing vibrational energies with MCTDH.


2008 ◽  
Vol 07 (04) ◽  
pp. 707-717 ◽  
Author(s):  
YALI CUI ◽  
HONG RAN ◽  
DAIQIAN XIE

Vibrationally averaged potential energy surfaces for isotopic He–CO 2 complexes ( He –18 O 13 C 18 O and He –16 O 13 C 16 O ) are presented. Based on the latest ab initio potential of He –16 O 12 C 16 O (Ran H, Xie D, J Chem Phys128:124323, 2008.) including the Q3 normal mode for the v3 antisymmetric stretching vibration of the CO 2 molecule, the averaged potentials for both He –18 O 13 C 18 O and He –16 O 13 C 16 O are obtained by integrating the potential energy surfaces over the Q3 normal mode. The averaged potentials have T-shaped global minima and two equivalent linear local minima. The radial discrete variable representation/angular finite basis representation method and Lanczos algorithm are employed to calculate the related rovibrational energy levels. The calculated band origin shifts of He –18 O 13 C 18 O and He –16 O 13 C 16 O are 0.1066 and 0.0914 cm-1, respectively, which agree very well with the observed values of 0.1123 and 0.0929 cm-1. The calculated rovibrational transitions of He –18 O 13 C 18 O and He –16 O 13 C 16 O are also in very good agreement with the available experimental spectra.


Sign in / Sign up

Export Citation Format

Share Document