A new ab initio intermolecular potential energy surface and predicted rotational spectra of the Kr−H2O complex

Abstract

We report a new three-dimensional ab initio intermolecular potential energy surface for the Kr-H(2)O complex with the H(2)O monomer fixed at its experimental averaged structure. Using the supermolecular approach, the intermolecular potential energies were evaluated at the coupled-cluster singles and doubles level with noniterative inclusion of connected triples with the full counterpoise correction for the basis set superposition error and a large basis set including bond functions. The global minimum corresponding to a planar H-bond configuration was located at the intermolecular distance of 3.82 Å with a well depth of 169.98 cm(-1). In addition, two first-order and one second-order saddle points were also identified. The combined radial discrete variable representation∕angular finite basis representation method and the Lanczos algorithm were employed to calculate the rovibrational energy levels for 16 isotopic species of the Kr-H(2)O complexes. The rotational transition frequencies, structure parameters, and nuclear quadrupole coupling constants were also determined for the ground and first intermolecular vibrational excited states and are all in good agreement with the available experimental values.

Analysis of a remarkable perpendicular band in Kr H2O with origin close to the ν1+ν3 R(0) line in H2O

“…The resulting set of energy levels around 3 overtones can be expected to be similar in Kr-H2O, as supported by ab initio calculations [13]. This implies that the band of interest of the present work, shown in Fig.…”

“…This can be possibly explained by the additional amount of energy released into the expansion when tuning conditions to form (H2O)2 (D0 = 1105 cm -1 [24]) rather than Kr-H2O (D0 = 119.461 cm -1 [13]) species.…”

“…Kr-H2O was previously studied in the gas phase in the microwave (MW) range [5] and in matrix [6]. Gas-phase collision-type experiments supported by theoretical calculations were also published [7,8], as well as pure ab initio investigations [9][10][11][12][13][14]. According to the theoretical literature, the Kr atom is oriented quite on line with one of the water O-H bonds, thus in the water plane [8,11].…”

Near infrared overtone (vOH = 2 ← 0) spectroscopy of Ne–H2O clusters

“…[13][14][15] Conversely, the greater ease of formation in cold supersonic jets has motivated exploration of the much heavier and more strongly bound rare gas dimers of H 2 O with Ar, Kr, and Xe, based on both direct absorption and vibrationally mediated photolysis (VMP) techniques in the mid, near, and far infrared region. 5,9,[16][17][18][19][20][21] In clear contrast, there has been much less experimental work on Ne-H 2 O for which the binding energies (D 0 ≈ 32 cm 1 for para H 2 O and D 0 ≈ 35 cm 1 for ortho H 2 O) and large amplitude internal rotor motion are thought to be intermediate between He-H 2 O (D 0 ≈ 6.8 cm 1 ) and Ar-H 2 O (D 0 ≈ 100 cm 1 ). 5,[22][23][24][25] There have been recent high resolution mid infrared spectra reported for Ne-H 2 O/D 2 O clusters in the HOH/DOD fundamental bend region, which now provide the first high resolution spectroscopic data for the bending manifold.…”

Vibrationally excited intermolecular potential energy surfaces and the predicted near infrared overtone (vOH = 2 ← 0) spectra of a H2O–Ne complex

“…[14][15][16][17][18][19] There has also been much spectroscopic exploration and theoretical simulation of the heavier and much more strongly bound rare gas dimers of H 2 O with Ar, Kr, and Xe. 10,[20][21][22][23][24][25][26][27][28][29] In clear contrast, there has been much less experimental and theoretical work on H 2 O-Ne for which the binding energies and large amplitude internal rotor motion are thought to be intermediate between H 2 O-He and H 2 O-Ar. 30,31 Theoretically, Bagno 32 found the most stable neon-water arrangement to be at r = 320 pm, y = 120 pm, with a counterpoise-corrected binding energy of À0.54 kJ mol À1 .…”