TY - JOUR

T1 - Cutoff radius effect of the isotropic periodic sum method in homogeneous system. II. Water

AU - Takahashi, Kazuaki

AU - Narumi, Tetsu

AU - Yasuoka, Kenji

N1 - Funding Information:
KT was supported by Grant-in-Aid for Japan Society for the Promotion of Science (JSPS) Fellows 21-5452 of The Ministry of Education, Culture, Sports, Science and Technology (MEXT). TN and KY were supported by the Core Research for the Evolution Science and Technology (CREST) of the Japan Science and Technology Corporation (JST).

PY - 2010/7/7

Y1 - 2010/7/7

N2 - Molecular dynamics simulation has been applied for water to compare the isotropic periodic sum (IPS) method [X. Wu and B. R. Brooks, J. Chem. Phys. 122, 044107 (2005)] with the Ewald sum based on the diffusion coefficient and liquid structure. The IPS method gives a good estimation for the self-diffusion coefficient at a cutoff radius, rc, greater than 2.2 nm; however, the radial distribution function g (r) has a notable deviation. The peak of this deviation appears at specific intermolecular distances which are near each cutoff radius and decrease in proportion to the inverse of the cube of r c. Thus the deviation becomes insignificant (less than 1%) at r c greater than 2.2 nm. The distance dependent Kirkwood factor G k (r) was also calculated, and since the truncation of a long-range interaction of the cutofflike method (such as cutoff with or without the switch function and the reaction field) shows serious shortcomings for dipole-dipole correlations in bulk water systems, this was observed by comparing the shape to that of the Ewald sum [Y. Yonetani, J. Chem. Phys. 124, 204501 (2006); D. van der Spoel and P. J. van Maaren, J. Chem. Theory Comput. 2, 1 (2006)]. The G k (r) of cutofflike method greatly deviate from that of the Ewald sum. However, the discrepancy of Gk (r) for the IPS method was found to be much less than that of other typical cutofflike methods. In conclusion, the IPS method is an adequately accurate technique for estimating transport coefficients and the liquid structure of water in a homogeneous system at long cutoff distances.

AB - Molecular dynamics simulation has been applied for water to compare the isotropic periodic sum (IPS) method [X. Wu and B. R. Brooks, J. Chem. Phys. 122, 044107 (2005)] with the Ewald sum based on the diffusion coefficient and liquid structure. The IPS method gives a good estimation for the self-diffusion coefficient at a cutoff radius, rc, greater than 2.2 nm; however, the radial distribution function g (r) has a notable deviation. The peak of this deviation appears at specific intermolecular distances which are near each cutoff radius and decrease in proportion to the inverse of the cube of r c. Thus the deviation becomes insignificant (less than 1%) at r c greater than 2.2 nm. The distance dependent Kirkwood factor G k (r) was also calculated, and since the truncation of a long-range interaction of the cutofflike method (such as cutoff with or without the switch function and the reaction field) shows serious shortcomings for dipole-dipole correlations in bulk water systems, this was observed by comparing the shape to that of the Ewald sum [Y. Yonetani, J. Chem. Phys. 124, 204501 (2006); D. van der Spoel and P. J. van Maaren, J. Chem. Theory Comput. 2, 1 (2006)]. The G k (r) of cutofflike method greatly deviate from that of the Ewald sum. However, the discrepancy of Gk (r) for the IPS method was found to be much less than that of other typical cutofflike methods. In conclusion, the IPS method is an adequately accurate technique for estimating transport coefficients and the liquid structure of water in a homogeneous system at long cutoff distances.

UR - http://www.scopus.com/inward/record.url?scp=77954576665&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77954576665&partnerID=8YFLogxK

U2 - 10.1063/1.3462241

DO - 10.1063/1.3462241

M3 - Article

C2 - 20614961

AN - SCOPUS:77954576665

VL - 133

JO - Journal of Chemical Physics

JF - Journal of Chemical Physics

SN - 0021-9606

IS - 1

M1 - 014109

ER -