Chen G, Goddard W A
Materials and Molecular Simulation Center, California Institute of Technology, Pasadena, CA 91125, USA.
Proc Natl Acad Sci U S A. 1993 Feb 15;90(4):1350-3. doi: 10.1073/pnas.90.4.1350.
Using electronic states and phonon states from the first-principles calculations and including both conventional electron-phonon charge coupling and Jahn-Teller coupling, we predict Tc and other superconducting properties. The only adjustable parameter in the theory is the screening length, Rsc. Using Rsc = 0.8-1.0 A, we find excellent agreement with experiment for Tc (16-18 K), pressure dependence of Tc (Delta Tc = -6 to -10 K for 1 GPa), and 12 C to 13 C isotope shift (alphaC = 0.2); experimental values: 19 K, -7 K, and 0.3, respectively.
利用第一性原理计算得到的电子态和声子态，并同时考虑传统的电子 - 声子电荷耦合和 Jahn - Teller 耦合，我们预测了超导转变温度（Tc）和其他超导性质。该理论中唯一的可调参数是屏蔽长度Rsc。使用Rsc = 0.8 - 1.0 Å时，我们发现对于Tc（16 - 18 K）、Tc的压力依赖性（1 GPa下ΔTc = -6至-10 K）以及12C到13C的同位素位移（αC = 0.2），理论与实验结果吻合得非常好；实验值分别为19 K、-7 K和0.3。
