Abstract
•The calculated values of bulk modulus in Reddy et al. [1] are now recalculated correctly.•Eq. (11) suggested by Reddy et al. [1] is not suitable to calculate the bulk modulus, B, for any element or material.•Eq. (12) in Ref. [1] is suitable to calculate, B, for all elements and materials except the underlined materials in Table 4.•All values of the electronic polarizability have been recalculated by different methods.•The bulk modulus, B, and microhardness parameter, H are different; Eq. (8) gives the relation between B and H.
In reference Reddy et al. (2009) the correlations between energy gap, optical electronegativity and electronic polarizability for different materials have been studied. The authors of this paper (Reddy et al., 2009) aimed to make extinction or complete some previous works (Bahadur and Mishra, 2013; Reddy et al., 1999, 2000, 1998, 2005, 2008; Reddy and Nazeer Ahammed, 1996; Oshcherin, 1979; Neumann, 1983, 1987; Deus and Schneider; 1985; Deus et al., 1983; Kumar et al. 1992). However, this paper (Reddy et al., 2009) contains many fundamental errors in the calculation of bulk modulus, especially Tables 4–6. As a result, all the obtained values of the bulk modulus and consequently the electronic polarizability are incorrect. Moreover in Table 4 (Reddy et al., 2009), the bulk modulus of II−VI group semiconductors have been calculated by substituting the values of the band gap, Eg, into Eq. (11) (B=14.91 Eg+23.3). The obtained values of B using Eq. (11) are conflicted with that calculated values of B based on the electronegativity and the published previously data. Therefore Eq. (11) in reference Reddy et al. (2009) is not suitable for calculating the values of B for any element or materials. When I recalculated the values of B for all materials in Tables 1 and 4–6 in paper (Reddy et al., 2009) using Eq. (12), I found that, Eq. (12) gives acceptable values of B for all materials except the underlined materials in Table 4 in the present note. The aim of this note is to recalculate both bulk modulus and electronic polarizability for all materials found in Reddy et al. (2009) to introduce the errors present in this paper.