In this work, we present the effect of electric field on 4-(trans-4 $$'$$ ′ -n-alkyl-cyclohexyl) isothiocyanate-benzene (nCHBT) liquid crystal (LC) molecules. Under the influence of an electric field, the birefringence exhibits the even–odd effect while order parameter, HOMO–LUMO gap, magic angle, isotropic polarisability, range of director angle and the refractive index do not exhibit any even–odd effect. The extension of the alkyl chain length of the nCHBT liquid crystal molecule exhibits the even–odd effect for the dipole moment and temperature from nematic to isotropic phase transition while the HOMO–LUMO gap remains constant. Still, order parameters, isotropic polarisability and refractive index have continuously increased. The odd carbon atom numbers present higher values than the even carbon atom numbers of the alkyl chain for the phase transition temperature. The nCHBT LC molecule expresses the order parameter, and birefringence is reciprocal to each other. For the whole series, there is an increase in order parameter, and a decrease in birefringence. The influence of the external electric field is an alternative to the temperature for the optical parameter of nCHBT LC.

中文翻译：

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同系nCHBT液晶分子在电场影响下的奇偶效应：一种理论方法

在这项工作中，我们展示了电场对 4-(trans-4 $$'$$ ' -n-烷基-环己基)异硫氰酸酯-苯 (nCHBT) 液晶 (LC) 分子的影响。在电场的影响下，双折射表现出奇偶效应，而有序参数、HOMO-LUMO 间隙、魔角、各向同性极化率、指向角范围和折射率不表现出任何奇偶效应。nCHBT 液晶分子的烷基链长度的延长对偶极矩和温度从向列相到各向同性相变表现出奇偶效应，而 HOMO-LUMO 间隙保持不变。尽管如此，有序参数、各向同性极化率和折射率仍在不断增加。对于相变温度，奇数碳原子数比烷基链的偶数碳原子数呈现更高的值。nCHBT LC分子表示有序参数，双折射互为倒数。对于整个系列，顺序参数增加，双折射减少。对于 nCHBT LC 的光学参数，外部电场的影响是温度的替代。