OC2H3CN
	Nitrogen
	Nuclear Quadrupole Coupling Constants
		in Oxiranecarbonitrile
	Calculation of the nitrogen nqcc's in oxiranecarbonitrile was made on a structure obtained by MP2/6-311+G(d,p) optimization with correction of the CN bond length as discussed below.  These are compared in Table 1 with the experimental nqcc's of Müller and Bauder [1].  Structure parameters are given in Table 2, atomic coordinates in Table 3, and rotational constants in Table 4.
	In Table 1, RMS is the root mean square difference between calculated and experimental diagonal nqcc's (percentage of the average of the magnitudes of the experimental nqcc's).  RSD is the calibration residual standard deviation of the B3PW91/6-311+G(df,pd) model for calculation of the nitrogen nqcc's.
	Subscripts a,b,c refer to the principal axes of the inertia tensor; x,y,z to the principal axes of the nqcc tensor.  Ø (degrees) is the angle between its subscripted parameters.  ETA = (Xxx - Xyy)/Xzz.
	Table 1. Nitrogen nqcc's in OC2H3CN (MHz).  Calculation was made on the MP2/6-311+G(d,p) optimized structure (as discussed below).     Calc. Expt. [1]     14N Xaa - 3.743 - 3.725(13) Xbb 2.016 2.010(14) Xcc 1.727 1.715(15) Xab 0.072 * Xac - 1.988 * Xbc 0.252 *   RMS 0.013 (0.53 %) RSD 0.030 (1.3 %)   Xxx 1.916 Xyy 2.477 Xzz - 4.393 ETA 0.128 Øz,a 18.09 Øz,b 91.31 Øz,c 71.96 Øz,CN   0.21
	* The algebraic signs of the off-diagonal components depend upon the orientation of the molecule with respect to a,b,c axes.  Here, the algebraic signs correspond to the atomic a,b,c coordinates given in Table 3.
	Molecular Structure
	The structure parameters given below are those obtained by optimization at the MP2/6-311+G(d,p) level of theory, with the exception of the CN bond length.  The CN bond length is corrected, according to the method of Demaison et al. [2].
	Table 2.  Molecular structure parameters, MP2/6-311+G(d,p), ropt (Å and degrees).   OC(1) 1.4324 Z-Matrix OC(2) 1.4328 C(1)C(2) 1.4746 C(1)H 1.0860 C(1)C 1.4504 CN 1.1566 C(2)Hc 1.0859 C(2)Ht 1.0859 C(1)CN 179.62 OC(2)C(1)   59.01 CC(1)H 115.21 HcC(2)Ht 117.23
	Table 3.  Oxiranecarbonitrile.  Atomic coordinates, ropt. (More figures are shown than are significant.)     a (Å)   b (Å)   c (Å) O 1.235984 - 0.706984 - 0.258562 C 0.306180 - 0.012321 0.580883 C 1.340538 0.719460 - 0.173469 C - 1.070945 0.012098 0.126359 N - 2.171134 0.035102 - 0.229698 H 0.438826 - 0.175096 1.646390 H 2.208398 1.088804 0.364659 H 1.047666 1.255084 - 1.071529
	Table 4. Oxiranecarbonitrile.  Rotational constants (MHz). Calc., ropt       Expt. [1] A 18 395.3 18 456.2955(29) B   3 520.7   3 524.70497(46) C   3 365.8   3 367.81108(42)
	[1] F.Müller and A.Bauder, J.Mol.Spectrosc. 179,61(1996).
	[2] J.Demaison, J.Cosléou, R.Bocquet, and A.G.Lesarri, J.Mol.Spectrosc. 167,400(1994).
	HCCCN		CH3CN		(CH3)3CCN
	C6H5CN		CH2CHCN
	Table of Contents
	Molecules/Nitrogen
						C3H3NO.html
						Last Modified 15 Nov 2005