Blueshift and intramolecular tunneling of NH3 umbrella mode in 4Hen clusters
J. Chem. Phys. 127, 194303 (2007); doi:10.1063/1.2787004
Published 16 November 2007
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We present diffusion Monte Carlo calculations of the ground and first excited vibrational states of NH3 4Hen for n
40. We use the potential energy surface developed by one of us [M. P. Hodges and R. J. Wheatley, J. Chem. Phys. 114, 8836 (2001)], which includes the umbrella mode coordinate of NH3. Using quantum Monte Carlo calculations of excited states, we show that this potential is able to reproduce qualitatively the experimentally observed effects of the helium environment, namely, a blueshift of the umbrella mode frequency and a reduction of the tunneling splittings in ground and first excited vibrational states of the molecule. These basic features are found to result regardless of whether dynamical approximations or exact calculations are employed.
©2007 American Institute of Physics
40. We use the potential energy surface developed by one of us [M. P. Hodges and R. J. Wheatley, J. Chem. Phys. 114, 8836 (2001)], which includes the umbrella mode coordinate of NH3. Using quantum Monte Carlo calculations of excited states, we show that this potential is able to reproduce qualitatively the experimentally observed effects of the helium environment, namely, a blueshift of the umbrella mode frequency and a reduction of the tunneling splittings in ground and first excited vibrational states of the molecule. These basic features are found to result regardless of whether dynamical approximations or exact calculations are employed.
©2007 American Institute of Physics
| History: | Received 15 May 2006; accepted 28 August 2007; published 16 November 2007 |
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http://link.aip.org/link/?JCPSA6/127/194303/1 |
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0021-9606 (print)
1089-7690 (online)
REFERENCES (45)
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- J. P. Toennies and A. F. Vilesov,
Annu. Rev. Phys. Chem. 49, 1 (1998) . - K. B. Whaley, in Advances in Molecular Vibrations and Collision Dynamics, edited by J. Bowman and Z. Bačić (Academic, New York/JAI, Greenwich, CT, 1998), Vol. III.
- C. Callegari, K. K. Lehmann, R. Schmied, and G. Scoles, J. Chem. Phys. 115, 10090 (2001).
- Y. Kwon, P. Huang, M. V. Patel, D. Blume, and K. B. Whaley, J. Chem. Phys. 113, 6469 (2000).
- J. P. Toennies and A. F. Vilesov,
Angew. Chem., Int. Ed. 43, 2622 (2004) . - M. Hartmann, R. E. Miller, A. F. Vilesov, and J. P. Toennies, Phys. Rev. Lett. 75, 1566 (1995).
- R. N. Barnett and K. B. Whaley, J. Chem. Phys. 99, 9730 (1993).
- F. Paesani, F. A. Gianturco, and K. B. Whaley, J. Chem. Phys. 115, 10225 (2001).
- D. Blume, M. Lewerenz, F. Huisken, and M. Kaloudis, J. Chem. Phys. 105, 8666 (1996).
- K. Nauta and R. E. Miller, J. Chem. Phys. 113, 9466 (2000).
- R. Fröchtenicht, M. Kaloudis, M. Koch, and F. Huisken, J. Chem. Phys. 105, 6128 (1996).
- K. Nauta and R. E. Miller, J. Chem. Phys. 113, 10158 (2000).
- M. Behrens, U. Buck, R. Fröchtenicht, M. Hartmann, and M. Havenith, J. Chem. Phys. 107, 7179 (1997).
- A. Sarsa, Z. Bačić, J. W. Moskowitz, and K. E. Schmidt, Phys. Rev. Lett. 88, 123401 (2002).
- H. Jiang, A. Sarsa, G. Murdachaew, K. Szalewicz, and Z. Bačić, J. Chem. Phys. 123, 224313 (2005).
- M. Behrens, U. Buck, R. Fröchtenicht, M. Hartmann, F. Huisken, and F. Rohmund, J. Chem. Phys. 109, 5914 (1998).
- M. N. Slipchenko and A. F. Vilesov,
Chem. Phys. Lett. 412, 176 (2005) . - After this paper was completed, we learned of a new experimental microwave study of NH3 in helium droplets [R. Lehnig, N. V. Blinov, and W. Jager, J. Chem. Phys., preprint, 2007 (submitted)] that shows a similar reduction of 8% in the ground state tunneling splitting relative to its gas phase value.
- M. P. Hodges and R. J. Wheatley, J. Chem. Phys. 114, 8836 (2001).
- G. Herzberg, Molecular Spectra and Molecular Structure II: Infrared and Raman Spectra of Polyatomic Molecules (Van Nostrand, Princeton, 1966).
- E. Lee, D. Farrelly, and K. B. Whaley, Phys. Rev. Lett. 83, 3812 (1999).
- D. Blume, M. Lewerenz, P. Niyaz, and K. B. Whaley, Phys. Rev. E 55, 3664 (1997).
- A. Viel and K. B. Whaley, J. Chem. Phys. 115, 10186 (2001).
- M. D. Coutinho-Neto, A. Viel, and U. Manthe, J. Chem. Phys. 121, 9207 (2004).
- A. Niño and C. Muñoz-Caro,
Comput. Chem. (Oxford) 19, 371 (1995) . - S. Urban, R. D'Cunha, K. N. Rao, and D. Papoušek,
Can. J. Phys. 62, 1775 (1984) . - S. A. Chin and E. Krotscheck, Phys. Rev. B 52, 10405 (1995).
- A. Viel, M. V. Patel, P. Niyaz, and K. B. Whaley,
Comput. Phys. Commun. 145, 24 (2002) . - R. A. Aziz, F. R. W. McCourt, and C. C. K. Wong,
Mol. Phys. 61, 1487 (1987) . - J. C. Light, I. P. Hamilton, and J. V. Lill, J. Chem. Phys. 82, 1400 (1985).
- C. Leforestier, J. Chem. Phys. 94, 6388 (1991).
- B. H. Wells,
Chem. Phys. Lett. 115, 89 (1985) . - M. Lewerenz, J. Chem. Phys. 104, 1028 (1996).
- M. P. Hodges (private communication).
- P. Huang, A. Viel, and K. B. Whaley, in Recent Advances in Quantum Monte Carlo Methods, Recent Advances in Computational Chemistry Vol. 2, edited by W. A. Lester, Jr., S. M. Rothstein, and S. Tanaka (World Scientific, Singapore, 2002), Pt. II, p. 111.
- P. J. Reynolds, D. M. Ceperley, B. J. Alder, and W. A. Lester, J. Chem. Phys. 77, 5593 (1982).
- M. A. Suhm and R. O. Watts,
Phys. Rep. 204, 293 (1991) . - V. Buch, J. Chem. Phys. 97, 726 (1992).
- C. J. Umrigar, M. P. Nightingale, and K. J. Runge, J. Chem. Phys. 99, 2865 (1993).
- B. L. Hammond, W. A. Lester, and P. J. Reynolds, Monte Carlo Methods in Ab Initio Quantum Chemistry (World Scientific, Singapore, 1994).
- A. Sarsa, K. E. Schmidt, and J. W. Moskowitz, J. Chem. Phys. 113, 44 (2000).
- R. Assaraf, M. Caffarel, and A. Khelif, Phys. Rev. E 61, 4566 (2000).
- A. Viel, M. D. Coutinho-Neto, and U. Manthe, J. Chem. Phys. 126, 024308 (2007).
- M. Lewerenz, J. Chem. Phys. 106, 4596 (1997).
- D. Blume and K. B. Whaley, J. Chem. Phys. 112, 2218 (2000).








