An ab initio molecular orbital study of the argon hydride molecule-ions, ArH+ and ArD+, at the MP4(SDQ)/6-311++G(3df,3dp) level. I. The dipole moment, charge distribution, energy levels, internuclear distance and potential energy of the X1Σ+ ground state of the 40Ar1H+ and 40Ar2D+ molecule-ions

Abstract

The X 1 Σ + state of the 40 Ar 1 H + and 40 Ar 2 D + was explored with an ab initio molecular orbital (MO) study (MP4, basis set 6-311++G(3df, 3pd), followed with SDQ): E Total =−527.182 771 62 hartree at R e =1.2767 A ̊ (Exp. 1.280 3730(11)); D e =33 509.189 cm −1 ; μ=1.9283 D . The potential energy (PE) follows a Morse curve with r 2 =0.9993. Vibrational term values are G 0 (ArH + )=1374.95 (ArD + : 964.83) cm −1 and G 1 (ArH + )=4038.13 (ArD + : 2788.47) cm −1 . Rotational constant B=315.406 897 GHz for 40 Ar 1 H + and 161.70 GHz for 40 Ar 2 D + (Exp. 158.702 3259(55) GHz). The energy level diagram and the electron density contours are discussed.