### Abstract

On the basis of quantum chemical calculations C^{α}-glycyl radical parameters have been developed for the OPLS-AA/L force field. The molecular mechanics hypersurface was fitted to the calculated quantum chemical surface by minimizing their molecular mechanics parameter dependent sum-of-squares deviations. To do this, a computer program in which the molecular mechanics energy derivatives with respect to the parameters were calculated analytically was developed, implementing the general method of Lifson and Warshel (J Chem Phys 1968, 49, 5116) for force field parameter optimization. This program, in principle, can determine the optimal parameter set in one calculation if enough representative value points on the quantum chemical potential energy surface are available and there is no linear dependency between the parameters. Some of the parameters in quantum calculations, including several new torsion types around a bond as well as angle parameters at a new central atom type, are not completely separable. Consequently, some restrictions and/or presumptions were necessary during parameter optimization. The relative OPLS-AA energies reproduced those calculated quantum chemically almost perfectly.

Original language | English |
---|---|

Pages (from-to) | 1999-2009 |

Number of pages | 11 |

Journal | Journal of Computational Chemistry |

Volume | 29 |

Issue number | 12 |

DOIs | |

State | Published - Sep 2008 |

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### All Science Journal Classification (ASJC) codes

- Chemistry(all)
- Safety, Risk, Reliability and Quality

### Cite this

*Journal of Computational Chemistry*,

*29*(12), 1999-2009. https://doi.org/10.1002/jcc.20962

**Development of glycyl radical parameters for the OPLS-AA/L force field.** / Komáromi, István; Owen, Michael C.; Murphy, Richard F.; Lovas, Sándor.

Research output: Contribution to journal › Article

*Journal of Computational Chemistry*, vol. 29, no. 12, pp. 1999-2009. https://doi.org/10.1002/jcc.20962

}

TY - JOUR

T1 - Development of glycyl radical parameters for the OPLS-AA/L force field

AU - Komáromi, István

AU - Owen, Michael C.

AU - Murphy, Richard F.

AU - Lovas, Sándor

PY - 2008/9

Y1 - 2008/9

N2 - On the basis of quantum chemical calculations Cα-glycyl radical parameters have been developed for the OPLS-AA/L force field. The molecular mechanics hypersurface was fitted to the calculated quantum chemical surface by minimizing their molecular mechanics parameter dependent sum-of-squares deviations. To do this, a computer program in which the molecular mechanics energy derivatives with respect to the parameters were calculated analytically was developed, implementing the general method of Lifson and Warshel (J Chem Phys 1968, 49, 5116) for force field parameter optimization. This program, in principle, can determine the optimal parameter set in one calculation if enough representative value points on the quantum chemical potential energy surface are available and there is no linear dependency between the parameters. Some of the parameters in quantum calculations, including several new torsion types around a bond as well as angle parameters at a new central atom type, are not completely separable. Consequently, some restrictions and/or presumptions were necessary during parameter optimization. The relative OPLS-AA energies reproduced those calculated quantum chemically almost perfectly.

AB - On the basis of quantum chemical calculations Cα-glycyl radical parameters have been developed for the OPLS-AA/L force field. The molecular mechanics hypersurface was fitted to the calculated quantum chemical surface by minimizing their molecular mechanics parameter dependent sum-of-squares deviations. To do this, a computer program in which the molecular mechanics energy derivatives with respect to the parameters were calculated analytically was developed, implementing the general method of Lifson and Warshel (J Chem Phys 1968, 49, 5116) for force field parameter optimization. This program, in principle, can determine the optimal parameter set in one calculation if enough representative value points on the quantum chemical potential energy surface are available and there is no linear dependency between the parameters. Some of the parameters in quantum calculations, including several new torsion types around a bond as well as angle parameters at a new central atom type, are not completely separable. Consequently, some restrictions and/or presumptions were necessary during parameter optimization. The relative OPLS-AA energies reproduced those calculated quantum chemically almost perfectly.

UR - http://www.scopus.com/inward/record.url?scp=47549104077&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=47549104077&partnerID=8YFLogxK

U2 - 10.1002/jcc.20962

DO - 10.1002/jcc.20962

M3 - Article

VL - 29

SP - 1999

EP - 2009

JO - Journal of Computational Chemistry

JF - Journal of Computational Chemistry

SN - 0192-8651

IS - 12

ER -