801 research outputs found
Charge-transfer induced large nonlinear optical properties of small Al Clusters: Al4M4
We investigate the linear and nonlinear electric polarizabilities of small
Al4M4 (M=Li, Na and K) clusters. Quantum chemical calculations reveal that
these compounds exhibit an exceptionally high magnitude of linear and nonlinear
optical (NLO) coefficients which are orders of magnitude higher than the
conventional pi-conjugated systems of similar sizes. We attribute such
phenomenal increase to non-centrosymmetricity incorporated in the systems by
the alkali atoms surrounding the ring leading to charge transfer with small
optical gap and low bond length alternation (BLA). Such a low magnitude of the
BLA from a different origin, suggests the possibility that these clusters are
aromatic in character and along with the large NLO coefficients they appear to
be better candidates for next generation NLO fabrication devices
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