Constructing Potential Energy Surface with Correlated Theory for Dipeptides Using Molecular Tailoring Approach |
| |
Authors: | Subodh S. Khire Nandini Gattadahalli Nalini D. Gurav Anmol Kumar Shridhar R. Gadre |
| |
Affiliation: | 1. RIKEN Center for Computational Science, Kobe, 650-0047 Japan;2. Department of Scientific Computing Modelling and Simulation, Savitribai Phule Pune University, Pune, 411 007 India;3. School of Pharmacy, University of Maryland, Baltimore, 20 Penn Street, HSFII, Baltimore, Maryland, 21201 U.S.A. |
| |
Abstract: | We demonstrate a cost-effective alternative employing the fragment-based molecular tailoring approach (MTA) for building the potential energy surface (PES) for two dipeptides viz. alanine-alanine and alanine-proline employing correlated theory, with augmented Dunning basis sets. About 1369 geometries are generated for each test dipeptide by systematically varying the dihedral angles and . These conformational geometries are partially optimized by relaxing all the other Z-matrix parameters, fixing the values of and . The MP2 level PES is constructed from the MTA-energies of chemically intact geometries using minimal hardware. The fidelity of MP2/aug-cc-pVDZ level PES is brought out by comparing it with its full calculation counterpart. Further, we bring out the power of the method by reporting the MTA-based CCSD/aug-cc-pVDZ level PES for these two dipeptides containing 498 and 562 basis functions respectively. |
| |
Keywords: | dipeptides fragmentation method molecular tailoring approach potential energy surfaces Ramachandran plots |
|
|