HCCCH2-CH2NC
		Nitrogen
	Nuclear Quadrupole Coupling Constants
	in 4-Isocyano-1-Butyne
	The microwave spectrum of 4-isocyano-1-butyne has been investigated by Samdal et al. [1].  Hyperfine structure due to 14N quadrupole coupling, however, was not resolved.
	Calculation of the 14N nuclear quadrupole coupling constant tensor in each of the following rotamers of the title molecule was made here on ropt molecular structures given by CCSD(T)/cc-pVTZ optimization [1]:
	antiperiplanar (ap)					synclinal (sc)
	In Tables 1 and 2 - which show the calculated nqcc tensors - 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.  Structure parameters are given in Z-matrix format in Table 3.
	RSD is the calibration residual standard deviation of the B3PW91/6-311+G(df,pd) model for calculation of the efg's/nqcc's.
	Table 1.  Nitrogen nqcc's in antiperiplanar 4-isocyano-1-butyne (MHz).  Calculation was made on CCSD(T)/cc-pVTZ ropt structure.     Calc Expt     14N Xaa 0.428 Xbb - 0.199 Xcc - 0.229 |Xab| 0.213   RSD 0.030 (1.3 %)   Xxx - 0.265 Xyy - 0.229 Xzz 0.494 ETA - 0.0720 Øz,a 17.08 Øa,NC 18.90 Øz,NC   1.82
	Table 2.  Nitrogen nqcc's in synclinal 4-isocyano-1-butyne (MHz).  Calculation was made on CCSD(T)/cc-pVTZ ropt structure.     Calc Expt     14N Xaa - 0.077 Xbb 0.269 Xcc - 0.192 Xab - 0.364 Xac - 0.120 Xbc 0.160   RSD 0.030 (1.3 %)   Xxx - 0.311 Xyy - 0.242 Xzz 0.553 ETA - 0.125 Øz,NC   0.86
	Table 3.  4-Isocyano-1-butyne CCSD(T)/cc-pVTZ optimized structure parameters (Å and degrees).  Atomic numbering is shown above.       # B3PW91/6-311+G(df,pd) prop scf=tight 4-Isocyano-1-butyne    0 1  C               C   1   B1  C   2   B2     1    A1  C   3   B3     2    A2    1    D1    0  N   1   B4     2    A3    3    D2    0  C   5   B5     1    A4    2    D3    0  H   4   B6     3    A5    2    D4    0  H   1   B7     5    A6    6    D5    0  H   1   B8     5    A7    6    D6    0  H   2   B9     1    A8    5    D7    0  H   2   B10   1    A9    5    D8    0       antiperiplanar        synclinal    B1     1.53492603    B2     1.46682670    B3     1.21111471    B4     1.42978854    B5     1.17751428    B6     1.06337150    B7     1.09007157    B8     1.09007157    B9     1.09202047    B10   1.09202047    A1   110.55121654    A2   178.29890253    A3   110.36658404    A4   178.35811225    A5   179.30177046    A6   108.66430699    A7   108.66430699    A8   109.31019027    A9   109.31019027    D1     0.00000000    D2   180.00000000    D3     0.00000000    D4   180.00000000    D5   121.15141637    D6  -121.15141637    D7    58.68480457    D8   -58.68480457    B1     1.53442821    B2     1.46643296    B3     1.21077555    B4     1.42842221    B5     1.17754863    B6     1.06326916    B7     1.09034436    B8     1.09066723    B9     1.09229121    B10   1.09295557    A1   112.41270353    A2   178.75375597    A3   111.37157904    A4   178.74311071    A5   179.48024946    A6   108.35861205    A7   108.23136028    A8   109.21235695    A9   108.02316640    D1     8.96751387    D2    64.50025736    D3     2.02765262    D4  -119.35566306    D5   123.56175131    D6  -118.75566925    D7   -57.66765835    D8  -174.39676763
	[1]  S.Samdal, H.Møllendal, and J.C.Guillemin, J.Phys.Chem. A 117,10304(2013).
	CH3NC		HCCNC		(CH3)3CNC		C6H5NC
	CNCN		CH3CH2NC		CH2=CHNC		CF3NC
	Table of Contents
	Molecules/Nitrogen
						HCCCH2CH2NC.html
						Last Modified 17 Oct 2013