TY - JOUR
T1 - Isotope effect in dihydrogen-bonded systems
T2 - Application of the analytical energy gradient method in the nuclear orbital plus molecular orbital theory
AU - Nakai, Hiromi
AU - Ikabata, Yasuhiro
AU - Tsukamoto, Yasuhiro
AU - Imamura, Yutaka
AU - Miyamoto, Kaito
AU - Hoshino, Minoru
N1 - Funding Information:
The calculations were performed, in part, at the Research Center for Computational Science (RCCS) of Okazaki National Research Institute. This study was partially supported by a Grant-in-Aid for Scientific Research on Priority Areas ‘Molecular Theory for Real Systems’ ‘KAKENHI 18066016’ from the Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan, the Nanoscience Program in the Next Generation Super Computing Project of MEXT, and the ‘Development of high-performance computational environment for quantum chemical calculation and its assessment’ from the Advanced Research Institute for Science and Engineering (RISE), Waseda University.
PY - 2007/10/21
Y1 - 2007/10/21
N2 - We investigate isotope effects in dihydrogen systems using the nuclear orbital plus molecular orbital (NOMO) theory, which simultaneously determines nuclear and electronic wave functions without the Born-Oppenheimer approximation. In order to estimate the vibrational averaging bond distances, the analytical energy gradients are used for the NOMO theory. The bond distances of three dihydrogen-bonded systems, namely H3NX+ XBeH, LiX XC2H and H2BX XF for X = H, D and T, are obtained. The X X bond distances decrease with respect to the substitution T D H, which is contrary to the behaviour of typical hydrogen bonds. This indicates that isotope effects strengthen the X X bond. This behaviour is analogous to the Ubbelohde effect observed in the solid phase.
AB - We investigate isotope effects in dihydrogen systems using the nuclear orbital plus molecular orbital (NOMO) theory, which simultaneously determines nuclear and electronic wave functions without the Born-Oppenheimer approximation. In order to estimate the vibrational averaging bond distances, the analytical energy gradients are used for the NOMO theory. The bond distances of three dihydrogen-bonded systems, namely H3NX+ XBeH, LiX XC2H and H2BX XF for X = H, D and T, are obtained. The X X bond distances decrease with respect to the substitution T D H, which is contrary to the behaviour of typical hydrogen bonds. This indicates that isotope effects strengthen the X X bond. This behaviour is analogous to the Ubbelohde effect observed in the solid phase.
KW - Analytical energy gradient
KW - Dihydrogen-bonded system
KW - Isotope effect
KW - Nuclear orbital plus molecular orbital theory
KW - Vibrational averaging shift
UR - http://www.scopus.com/inward/record.url?scp=38849166113&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=38849166113&partnerID=8YFLogxK
U2 - 10.1080/00268970701618416
DO - 10.1080/00268970701618416
M3 - Article
AN - SCOPUS:38849166113
VL - 105
SP - 2649
EP - 2657
JO - Molecular Physics
JF - Molecular Physics
SN - 0026-8976
IS - 19-22
ER -