Rydberb bonding in (NH{sub 4}){sub 2}

Journal Article · Thu Oct 29 04:00:00 EST 1992 · Journal of Physical Chemistry

DOI:https://doi.org/10.1021/j100201a029· OSTI ID:458800

Boldyrev, A I; Simons, J ^[1]

---

1. Univ. of Utah, Salt Lake City, UT (United States)

Chemical binding of two monovalent Rydberg species to form a singlet-state Rydberg dimer molecule is predicted to be possible Ab initio electronic structure methods that include electron correlation (at levels up through QCISD(T)/6-31++G** MP2(full)/6-31++G** + ZPE) are shown to be essential to achieving a proper description of such bonding. The (NH{sub 4}) molecule, selected as the prototype for this study, is shown to be bound with respect to its Rydberg-species fragments, 2NH{sub 4} by 7.5-9.7 kcal/mol, depending on the level of treatment of electron correlation, and to be electronically stable (by ca.4 eV) with respect to (NH{sub 4}){sub 2}{sup +} at the neutral`s equilibrium geometry. The (NH{sub 4}){sub 2} Rydberg dimer is thermodynamically unstable with respect to 2NH{sub 3} + H{sub 2} by 86-89 kcal/mol mol yet possesses all real vibrational frequencies; it is thus a metastable molecular held together by a weak Rydberg bond. The dissociation energy of the (NH{sub 4}){sub 2}{sup +} cation to form NH{sub 4}{sup +} + NH{sub 4} is found to be larger than that of the neutral (NH{sub 4}){sub 2}. 12 refs., 4 figs., 9 tabs.

• Sponsoring Organization: USDOE
• OSTI ID: 458800
• Journal Information: Journal of Physical Chemistry, Journal Name: Journal of Physical Chemistry Journal Issue: 22 Vol. 96; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
40 CHEMISTRY
66 PHYSICS
CHEMICAL BONDS
DIMERS
DISSOCIATION
ELECTRON CORRELATION
ELECTRONIC STRUCTURE
NITROGEN HYDRIDES
RYDBERG STATES