Enhanced linear and nonlinear polarizabilities for the Li-4 cluster. How satisfactory is the agreement between theory and experiment for the static dipole polarizability?
G. Maroulis et D. Xenides, Enhanced linear and nonlinear polarizabilities for the Li-4 cluster. How satisfactory is the agreement between theory and experiment for the static dipole polarizability?, J PHYS CH A, 103(24), 1999, pp. 4590-4593
Highly accurate ab initio calculations with specially designed basis sets a
re reported for Li-4. The molecule emerges as a particularly soft system, w
ith a very anisotropic dipole polarizability and a very large second dipole
hyperpolarizability. An extensive investigation of basis set and electron
correlation effects leads to values of <(alpha)over bar> = 387.01 and Delta
alpha = 354.60 e(2)a(0)(2)E(h)(-1). The mean hyperpolarizability is <(gamm
a)over bar> = 2394 x 10(3) e(4)a(0)(4)E(h)(-3). The computational aspects o
f the present effort are discussed in view of the extension of quantumchemi
cal studies to large lithium clusters. Our values for the mean dipole polar
izability are systematically higher than the recently reported experimental
static value (326.6 e(2)a(0)(2)E(h)(-1)) of this important quantity [Benic
hou et al. Phys. Rev. A 1999, 59, R1].