Skip to main content
. Author manuscript; available in PMC: 2014 Feb 17.
Published in final edited form as: J Chem Phys. 2012 Dec 14;137(22):224309. doi: 10.1063/1.4769791

TABLE IV.

VMC equilibrium structures of cyclobutene calculated for both basis sets with the ECP pseudopotential, compared with other quantum chemistry calculations and experimental results from microwave spectra.

RC2C3
(Å)		 RC1C2
(Å)		 RC1C4
(Å)		 θC1C2C3
(deg)
VMC1 1.3352(2) 1.5135(2) 1.5642(3) 94.339(6)
vmc2 1.3343(2) 1.5135(2) 1.5625(5) 94.324(10)
HFa 1.323 1.515 1.562 94.5
MP2b 1.350 1.519 1.569 94.1
MP2a 1.347 1.513 1.564 94.1
LDAb 1.338 1.502 1.554 94.2
NL-SCFb 1.346 1.525 1.579 94.3
ACMa 1.340 1.513 1.565 94.3
BLYPa 1.352 1.529 1.586 94.4
B3LYPc 1.339 1.519 1.573 94.4
MWd 1.342(4) 1.517(3) 1.566(3) 94.2
a

Calculations with 6-31G* from Ref. 38.

b

MP2 calculations were done with 6-311G** basis sets, while the LDA and NL-SCF calculations were done using the TZ+2P basis set; from Ref. 41.

c

With basis set 6-311++G** from Ref. 43.

d

Microwave spectra from Ref. 79.