Title: The band energy structure of RbKSO₄ crystals
Author(s):

	O.V.Bovgyra (Franko Lviv National University, Kyrylo and Mefodij, 8str., Lviv, 79005 Ukraine) ,
	V.Yo.Stadnyk (Franko Lviv National University, Kyrylo and Mefodij, 8str., Lviv, 79005 Ukraine) ,
	A.V.Franiv (Franko Lviv National University, Kyrylo and Mefodij, 8str., Lviv, 79005 Ukraine) ,
	M.R.Tuzyak (Franko Lviv National University, Kyrylo and Mefodij, 8str., Lviv, 79005 Ukraine) ,
	O.Z.Chyzh (Franko Lviv National University, Kyrylo and Mefodij, 8str., Lviv, 79005 Ukraine)

The energy band structure of mechanically free and compressed RbKSO₄ single crystals is investigated. It is established that the top of the valence band is located at the D point of the Brillouin zone [k = (0.5, 0.5, 0)], the bottom of the conduction band lies at the Γ point, and the minimum direct band gap E_g is equal to 5.80 eV. The bottom of the conduction band is predominantly formed by the K s, Li p, Rb s, and Rb p states hybridized with the S p and O p antibonding states. The pressure coefficients of the energy position of the valence and conduction band states and the band gap E_g are determined.

Key words: uniaxial pressure, energy band, structure, valence band, conduction band
PACS: 71.20.Ps, 78.20.Ci