title: External factor variable connectivity index.
abstract: A new variable index, external factor variable connectivity index (EFVCI), is proposed, in which the atomic attribute is divided into two parts. The innate part is denoted as outer-shell electrons and external part or perturbation by other atoms is represented as summation, multiplied by a variable x, of squared reciprocal matrix of i row (corresponds to atom A(i)). The division of atomic attribute in EFVCI is interpreted by using topological structure. In the correlation of boiling point of 149 acyclic alkanes, the optimal values will approach to a constant at -0.29 by using the zero to higher order indices of the same series. The new index, with high regression quality (R = 0.9986, s = 2.26, and F = 7088.4), is compared favorably with variable connectivity index and molecular connectivity index.
authors.affiliation: Institute of Chemometrics and Intelligent Analytical Instruments, College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, P. R. China.
authors.forename: Qian-Nan
authors.initials: QN
authors.lastname: Hu
authors.forename: Yi-Zeng
authors.initials: YZ
authors.lastname: Liang
authors.forename: Ya-Li
authors.initials: YL
authors.lastname: Wang
authors.forename: Cheng-Jian
authors.initials: CJ
authors.lastname: Xu
authors.forename: Zhong-Da
authors.initials: ZD
authors.lastname: Zeng
authors.forename: Kai-Tai
authors.initials: KT
authors.lastname: Fang
authors.forename: Xiao-Ling
authors.initials: XL
authors.lastname: Peng
authors.forename: Yin
authors.initials: Y
authors.lastname: Hong