<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>0035-001X</journal-id>
<journal-title><![CDATA[Revista mexicana de física]]></journal-title>
<abbrev-journal-title><![CDATA[Rev. mex. fis.]]></abbrev-journal-title>
<issn>0035-001X</issn>
<publisher>
<publisher-name><![CDATA[Sociedad Mexicana de Física]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S0035-001X2022000600012</article-id>
<article-id pub-id-type="doi">10.31349/revmexfis.68.061003</article-id>
<title-group>
<article-title xml:lang="en"><![CDATA[Structural, electronic and optical properties of the wide band gap semiconductors KGaQ2 (Q = S, Se) and of AGaTe2 (A = K, Cs)]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Benmekideche]]></surname>
<given-names><![CDATA[N.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Fetah]]></surname>
<given-names><![CDATA[S.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Belgoumri]]></surname>
<given-names><![CDATA[Gh.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Bentabet]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Benmakhlouf]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,University of Bordj Bou-Arreridj Faculty of SNVSTU Laboratoire de Caractèisation et Valorisation des Ressources Naturelles]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Algeria</country>
</aff>
<aff id="Af2">
<institution><![CDATA[,University of Msila Faculty of science Laboratory of Materials and renewable energies]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Algeria</country>
</aff>
<aff id="Af3">
<institution><![CDATA[,University of Bordj Bou-Arreridj Faculty of SNVSTU Laboratoire de Caractèisation et Valorisation des Ressources Naturelles]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Algeria</country>
</aff>
<aff id="Af4">
<institution><![CDATA[,University of Bordj Bou-Arreridj Faculty of SNVSTU Laboratoire de Caractèisation et Valorisation des Ressources Naturelles]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Algeria</country>
</aff>
<aff id="Af5">
<institution><![CDATA[,University of Bordj Bou-Arreridj Faculty of SNVSTU Laboratoire de Caractèisation et Valorisation des Ressources Naturelles]]></institution>
<addr-line><![CDATA[ ]]></addr-line>
<country>Algeria</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>12</month>
<year>2022</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>12</month>
<year>2022</year>
</pub-date>
<volume>68</volume>
<numero>6</numero>
<fpage>0</fpage>
<lpage>0</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_arttext&amp;pid=S0035-001X2022000600012&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_abstract&amp;pid=S0035-001X2022000600012&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_pdf&amp;pid=S0035-001X2022000600012&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="en"><p><![CDATA[Abstract In this paper, we studied the structural, electronic and some optical properties of KGaQ2 (Q = S, Se) and AGaTe2 (A = K, Cs) crystals using the pseudopotential plane-wave (PP-PW) method based on density functional theory (DFT), the generalized gradient approximation (GGA) parameterized by Perdew-Burke-Ernzerhof (GGA-PBE) is used for the exchange-correlation (XC) potential. We also use the hybrid density functional (HSE06) to study the electronic structures of these materials. Our results for the equilibrium lattice constants (a, b and c), angle &#946; are in good agreement with experiment data. The electronic structure calculation suggested that crystals are direct-gap semiconductors, employing both the Perdew-Burke-Ernzerhof (PBE) and the hybrid (HSE06) functionals. We note that the hybrid density functional improved the value of band gap, and that the studied compounds are semiconductors with wide band-gaps. We have also predicted the optical properties; the refractive index, the reflection coefficient and dielectric constant on high frequencies.]]></p></abstract>
<kwd-group>
<kwd lng="en"><![CDATA[Density functional theory]]></kwd>
<kwd lng="en"><![CDATA[GGA-PBE]]></kwd>
<kwd lng="en"><![CDATA[HSE06]]></kwd>
<kwd lng="en"><![CDATA[KGaQ2 (Q = S, Se)]]></kwd>
<kwd lng="en"><![CDATA[AGaTe2 (A = K, Cs)]]></kwd>
<kwd lng="en"><![CDATA[Structural properties]]></kwd>
<kwd lng="en"><![CDATA[Electronic properties]]></kwd>
<kwd lng="en"><![CDATA[Optical constants]]></kwd>
</kwd-group>
</article-meta>
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