Acceleration of self-consistent-field convergence in ab initio molecular dynamics and Monte Carlo simulations and geometry optimization

Atsumi, Teruo; Nakai, Hiromi

doi:10.1016/j.cplett.2010.03.012

Cited by 15 publications

(23 citation statements)

References 19 publications

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“…We note that the time period of the dynamics is 100 ps, in contrast to most earlier studies, which are restricted to within 10 ps. 20,21 The results using the zero charges (ZRC) (top panel) are stable for values of the convergence criterion below 10 −4 hartree; of the latter values, large energy fluctuation occurs although there is no overall drift. By contrast, for the PRC calculations, although the energy fluctuations are small, there is significant energy drift.…”

Section: Fmentioning

confidence: 99%

“…However, when extrapolating wavefunctions, one should be cautious to maintain a consistent gauge of the wavefunctions at each geometric step. 20,32 The gauge consistency issue arises due to the invariance of unitary rotations in the occupied orbital space. This issue is not present in charge or Fock matrix element extrapolation.…”

Section: Fock Matrix Extrapolationmentioning

confidence: 99%

“…The slow step in BOMD is the convergence of the SCF iterations so that considerable effort is being invested to accelerate this aspect of the method. [18][19][20][21][22][23] The new algorithms extrapolate electronic variables (e.g., the Fock matrix) to accelerate SCF convergence. 21 Two types of extrapolations have been used.…”

Section: Introductionmentioning

confidence: 99%

“…This has been found to significantly improve SCF convergence. 20,21 The second category is "geometric" extrapolation, in which the geometry of the current step is approximated as linear combination of previous step geometries and the electronic variables are extrapolated with the same linear combination of steps. 19,20 In the least-square fitting of molecular orbital coefficients method, 20 the coefficients of the linear combination are obtained by the direct inversion in the iterative subspace method.…”

Section: Introductionmentioning

confidence: 99%

“…20,21 The second category is "geometric" extrapolation, in which the geometry of the current step is approximated as linear combination of previous step geometries and the electronic variables are extrapolated with the same linear combination of steps. 19,20 In the least-square fitting of molecular orbital coefficients method, 20 the coefficients of the linear combination are obtained by the direct inversion in the iterative subspace method. 24 Both the time and geometric extrapolation algorithms have demonstrated encouraging acceleration of the SCF convergence, but the lack of stability of the dynamical propagation calculated with these algorithms can create problems.…”

Section: Introductionmentioning

confidence: 99%

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Lagrangian formulation with dissipation of Born-Oppenheimer molecular dynamics using the density-functional tight-binding method

Zheng

Niklasson

Karplus

2011

The Journal of Chemical Physics

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An important element determining the time requirements of Born-Oppenheimer molecular dynamics (BOMD) is the convergence rate of the self-consistent solution of Roothaan equations (SCF). We show here that improved convergence and dynamics stability can be achieved by use of a Lagrangian formalism of BOMD with dissipation (DXL-BOMD). In the DXL-BOMD algorithm, an auxiliary electronic variable (e.g., the electron density or Fock matrix) is propagated and a dissipative force is added in the propagation to maintain the stability of the dynamics. Implementation of the approach in the self-consistent charge density functional tight-binding method makes possible simulations that are several hundred picoseconds in lengths, in contrast to earlier DFT-based BOMD calculations, which have been limited to tens of picoseconds or less. The increase in the simulation time results in a more meaningful evaluation of the DXL-BOMD method. A comparison is made of the number of iterations (and time) required for convergence of the SCF with DXL-BOMD and a standard method (starting with a zero charge guess for all atoms at each step), which gives accurate propagation with reasonable SCF convergence criteria. From tests using NVE simulations of C 2 F 4 and 20 neutral amino acid molecules in the gas phase, it is found that DXL-BOMD can improve SCF convergence by up to a factor of two over the standard method. Corresponding results are obtained in simulations of 32 water molecules in a periodic box. Linear response theory is used to analyze the relationship between the energy drift and the correlation of geometry propagation errors.

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Section: Fmentioning

confidence: 99%

Section: Fock Matrix Extrapolationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Lagrangian formulation with dissipation of Born-Oppenheimer molecular dynamics using the density-functional tight-binding method

Zheng

Niklasson

Karplus

2011

The Journal of Chemical Physics

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Acceleration of self‐consistent field convergence in ab initio molecular dynamics simulation with multiconfigurational wave function

Okoshi

Nakai

2014

J Comput Chem

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The Lagrange interpolation of molecular orbital (LIMO) method, which reduces the number of self-consistent field iterations in ab initio molecular dynamics simulations with the Hartree-Fock method and the Kohn-Sham density functional theories, is extended to the theory of multiconfigurational wave functions. We examine two types of treatments for the active orbitals that are partially occupied. The first treatment, as denoted by LIMO(C), is a simple application of the conventional LIMO method to the union of the inactive core and the active orbitals. The second, as denoted by LIMO(S), separately treats the inactive core and the active orbitals. Numerical tests to compare the two treatments clarify that LIMO(S) is superior to LIMO(C). Further applications of LIMO(S) to various systems demonstrate its effectiveness and robustness.

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Dcdftbmd: Divide‐and‐Conquer Density Functional Tight‐Binding Program for Huge‐System Quantum Mechanical Molecular Dynamics Simulations

Nishimura

Nakai

2019

J Comput Chem

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Dcdftbmd is a Fortran 90/95 program that enables efficient quantum mechanical molecular dynamics (MD) simulations using divide‐and‐conquer density functional tight‐binding (DC‐DFTB) method. Based on the remarkable performance of previous massively parallel DC‐DFTB energy and gradient calculations for huge systems, the code has been specialized to MD simulations. Recent implementations and modifications including DFTB extensions, improved computational speed in the DC‐DFTB computational steps, algorithms for efficient initial guess charge prediction, and free energy calculations via metadynamics technique have enhanced the capability to obtain atomistic insights in novel applications to nanomaterials and biomolecules. The energy, structure, and other molecular properties are also accessible through the single‐point calculation, geometry optimization, and vibrational frequency analysis. The available functionalities are outlined together with efficiency tests and simulation examples. © 2019 Wiley Periodicals, Inc.

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Acceleration of self-consistent-field convergence in ab initio molecular dynamics and Monte Carlo simulations and geometry optimization

Cited by 15 publications

References 19 publications

Lagrangian formulation with dissipation of Born-Oppenheimer molecular dynamics using the density-functional tight-binding method

Lagrangian formulation with dissipation of Born-Oppenheimer molecular dynamics using the density-functional tight-binding method

Acceleration of self‐consistent field convergence in ab initio molecular dynamics simulation with multiconfigurational wave function

Dcdftbmd: Divide‐and‐Conquer Density Functional Tight‐Binding Program for Huge‐System Quantum Mechanical Molecular Dynamics Simulations

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