TY - JOUR
T1 - Direct dynamics simulations using Hessian-based predictor-corrector integration algorithms
AU - Lourderaj, Upakarasamy
AU - Song, Kihyung
AU - Windus, Theresa L.
AU - Zhuang, Yu
AU - Hase, William L.
N1 - Funding Information:
This material is based upon work supported by the National Science Foundation under Grant Nos. CHE-0412677 and CHE-0615321, the Robert A. Welch Foundation under Grant No. D-0005, and the MSCF/PNNL Computational Grand Challenge Project GC3556. The authors thank Srirangam Addepalli and the High-Performance Computing Center at Texas Tech University for their support.
PY - 2007
Y1 - 2007
N2 - In previous research [J. Chem. Phys. 111, 3800 (1999)] a Hessian-based integration algorithm was derived for performing direct dynamics simulations. In the work presented here, improvements to this algorithm are described. The algorithm has a predictor step based on a local second-order Taylor expansion of the potential in Cartesian coordinates, within a trust radius, and a fifth-order correction to this predicted trajectory. The current algorithm determines the predicted trajectory in Cartesian coordinates, instead of the instantaneous normal mode coordinates used previously, to ensure angular momentum conservation. For the previous algorithm the corrected step was evaluated in rotated Cartesian coordinates. Since the local potential expanded in Cartesian coordinates is not invariant to rotation, the constants of motion are not necessarily conserved during the corrector step. An approximate correction to this shortcoming was made by projecting translation and rotation out of the rotated coordinates. For the current algorithm unrotated Cartesian coordinates are used for the corrected step to assure the constants of motion are conserved. An algorithm is proposed for updating the trust radius to enhance the accuracy and efficiency of the numerical integration. This modified Hessian-based integration algorithm, with its new components, has been implemented into the VENUS/NWChem software package and compared with the velocity-Verlet algorithm for the H2 CO→ H2 +CO, O3 + C3 H6, and F- +C H3 OOH chemical reactions.
AB - In previous research [J. Chem. Phys. 111, 3800 (1999)] a Hessian-based integration algorithm was derived for performing direct dynamics simulations. In the work presented here, improvements to this algorithm are described. The algorithm has a predictor step based on a local second-order Taylor expansion of the potential in Cartesian coordinates, within a trust radius, and a fifth-order correction to this predicted trajectory. The current algorithm determines the predicted trajectory in Cartesian coordinates, instead of the instantaneous normal mode coordinates used previously, to ensure angular momentum conservation. For the previous algorithm the corrected step was evaluated in rotated Cartesian coordinates. Since the local potential expanded in Cartesian coordinates is not invariant to rotation, the constants of motion are not necessarily conserved during the corrector step. An approximate correction to this shortcoming was made by projecting translation and rotation out of the rotated coordinates. For the current algorithm unrotated Cartesian coordinates are used for the corrected step to assure the constants of motion are conserved. An algorithm is proposed for updating the trust radius to enhance the accuracy and efficiency of the numerical integration. This modified Hessian-based integration algorithm, with its new components, has been implemented into the VENUS/NWChem software package and compared with the velocity-Verlet algorithm for the H2 CO→ H2 +CO, O3 + C3 H6, and F- +C H3 OOH chemical reactions.
UR - http://www.scopus.com/inward/record.url?scp=33847691891&partnerID=8YFLogxK
U2 - 10.1063/1.2437214
DO - 10.1063/1.2437214
M3 - Article
AN - SCOPUS:33847691891
VL - 126
JO - The Journal of Chemical Physics
JF - The Journal of Chemical Physics
SN - 0021-9606
IS - 4
M1 - 044105
ER -