Electronic properties and Compton scattering studies of monoclinic tungsten dioxide

• Presented first-ever Compton profile (CP) measurements on WO2.
• Analyzed CP data in terms of LCAO–DFT calculations.
• Discussed energy band, DOS and Mulliken׳s population.
• Discussed equally scaled CPs and bonding of isoelectronic WO2, WS2 and WSe2.
• Reported metallic character and Fermi surface topology of WO2.

We present the first ever Compton profile measurement of WO2 using a 20 Ci 137Cs γ-ray source. The experimental data have been used to test different approximations of density functional theory in linear combination of atomic orbitals (LCAO) scheme. It is found that theoretical Compton profile deduced using generalized gradient approximation (GGA) gives a better agreement than local density approximation and second order GGA. The computed energy bands, density of states and Mulliken׳s populations (MP) data confirm a metal-like behavior of WO2. The electronic properties calculated using LCAO approach are also compared with those obtained using full potential linearized augmented plane wave method. The nature of bonding in WO2 is also compared with isoelectronic WX2 (X=S, Se) compounds in terms of equal-valence-electron-density profiles and MP data, which suggest an increase in ionic character in the order WSe2→WS2→WO2.