Geometry optimization in delocalized internal coordinates: An efficient quadratically scaling algorithm for large molecules

1999 ◽  
Vol 110 (11) ◽  
pp. 4986-4991 ◽  
Author(s):  
Jon Baker ◽  
Don Kinghorn ◽  
Peter Pulay
Keyword(s):  
Geometry Optimization ◽  
Large Molecules ◽  
Internal Coordinates

An efficient direct method for geometry optimization of large molecules in internal coordinates

1998 ◽  
Vol 109 (16) ◽  
pp. 6571-6576 ◽  
Author(s):  
Béla Paizs ◽  
Géza Fogarasi ◽  
Peter Pulay
Keyword(s):  
Direct Method ◽  
Geometry Optimization ◽  
Large Molecules ◽  
Internal Coordinates

CLB18: A New Structural Database with Unusual Carbon–Carbon Long Bonds

2020 ◽  
Author(s):  
Pierpaolo Morgante ◽  
Roberto Peverati
Keyword(s):  
Transition Metal Complexes ◽  
Low Cost ◽  
Geometry Optimization ◽  
Structure Calculation ◽  
Unique Property ◽  
Spin States ◽  
Calculation Methods ◽  
Large Molecules ◽  
Barrier Heights ◽  
Structural Database

<div><div><div><p>In this Letter, we introduce a new database called carbon long bond 18 (CLB18), composed of 18 structures with one long C–C bond. We use this new database to evaluate the performance of several low-cost methods commonly used for geometry optimization of medium and large molecules. We found that the long bonds in CLB18 are electronically different from those found in barrier heights databases. We also report the unexpected correlation between the results of CLB18 and those of the energetics of spin states in transition-metal complexes. Given this unique property, CLB18 can be a useful tool for assessing existing electronic structure calculation methods and developing new ones.</p></div></div></div>

XO: An extended ONIOM method for accurate and efficient geometry optimization of large molecules

2010 ◽  
Vol 498 (1-3) ◽  
pp. 203-208 ◽  
Author(s):  
Wenping Guo ◽  
Anan Wu ◽  
Xin Xu
Keyword(s):  
Geometry Optimization ◽  
Large Molecules ◽  
Oniom Method

A new module for constrained multi-fragment geometry optimization in internal coordinates implemented in the MOLCAS package

2013 ◽  
Vol 34 (30) ◽  
pp. 2657-2665 ◽  
Author(s):  
Victor P. Vysotskiy ◽  
Jonas Boström ◽  
Valera Veryazov
Keyword(s):  
Geometry Optimization ◽  
Internal Coordinates

Geometry optimization in redundant internal coordinates

1992 ◽  
Vol 96 (4) ◽  
pp. 2856-2860 ◽  
Author(s):  
P. Pulay ◽  
G. Fogarasi
Keyword(s):  
Geometry Optimization ◽  
Internal Coordinates

Geometry optimization of solids using delocalized internal coordinates

2001 ◽  
Vol 335 (3-4) ◽  
pp. 321-326 ◽  
Author(s):  
Jan Andzelm ◽  
R.D. King-Smith ◽  
George Fitzgerald
Keyword(s):  
Geometry Optimization ◽  
Internal Coordinates

MOLECULAR TAILORING APPROACH: TOWARDS PC-BASED AB INITIO TREATMENT OF LARGE MOLECULES

2006 ◽  
Vol 05 (04) ◽  
pp. 835-855 ◽  
Author(s):  
SHRIDHAR R. GADRE ◽  
V. GANESH
Keyword(s):  
Ab Initio ◽  
Electron Density ◽  
Large Scale ◽  
Dipole Moments ◽  
Geometry Optimization ◽  
Parent Molecule ◽  
Large Molecules ◽  
Self Consistent Field ◽  
Moller Plesset ◽  
Molecular Tailoring

The development of a fragmentation-based scheme, viz. molecular tailoring approach (MTA) for ab initio computation of one-electron properties and geometry optimization is described. One-electron properties such as the molecular electrostatic potential (MESP), molecular electron density (MED), and dipole moments are computed by synthesizing the density matrix (DM) of the parent molecule from DMs of its small overlapping fragments. The electron density obtained via MTA was found to be typically within 0.5% of its actual counterpart, while maximum errors of about 2% were noticed in the case of the dipole moment and MESP distribution. An attempt is made to develop MTA-based geometry optimization that involves picking relevant energy gradients from fragment self-consistent field (SCF) calculations, bypassing the CPU and memory extensive SCF step of the complete molecule. This is based on the observation that the MTA gradients mimic the actual ones fairly well. As the calculations on individual fragments are mutually independent, this algorithm is amenable to large-scale parallelization and has been extended to a distributed setup of PCs. The code developed is put to test on γ-cyclodextrin, taxol, and a small albumin-binding protein (1prb) for one-electron properties. Further, molecules such as γ-cyclodextrin, taxol, a silicalite, and 1prb are subjected to MTA-based geometry optimization, on a PC cluster. The results indicate a favorable speedup of two to three times over the actual computations in the initial phase of optimization. Furthermore, it enables computations otherwise not possible on a PC. Preliminary results indicate similar savings with sustained accuracy even for large molecules at the level of Møller–Plesset second order perturbation (MP2) theory.

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