title: Theoretical study of the hydrogen bonding and infrared spectroscopy in the cis-vacant polymorph of dioctahedral 2:1 phyllosilicates.
abstract: The spatial geometry and local environment of hydroxyl groups of the cis-vacant (cv) crystal polymorph of dioctahedral 2:1 phyllosilicates are studied by computational methods, doing especial emphasis on the hydrogen bonds and electrostatic interactions of the hydroxyl groups with the neighbor atoms. Different types of phyllosilicates are explored: with only tetrahedral charge, with only octahedral charge, with simultaneous octahedral and tetrahedral substitution, and with different interlayer cation (IC). The effect of these interactions on the spectroscopic properties of these hydroxyl groups is also studied. All results are compared with the trans-vacant (tv) crystal forms of these minerals. Frequency differences between cv and tv polymorphs are smaller than those due to the local environments of these OH groups. This means that the changes in the interactions of the different local environments of each OH group are greater than the cv/tv differences.
authors.affiliation: Instituto de Astrofísica de Andalucía (CSIC), Glorieta de la Astronomía s/n, 18008, Granada, Spain, roa@iaa.es.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Escamilla-Roa
authors.forename: Alfonso
authors.initials: A
authors.lastname: Hernández-Laguna
authors.forename: C Ignacio
authors.initials: CI
authors.lastname: Sainz-Díaz
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry; D002412:Cations; D003198:Computer Simulation; D003460:Crystallization; D006860:Hydrogen Bonding; D006878:Hydroxides / Q000737:chemistry*; D017633:Magnesium Silicates / Q000737:chemistry; D008956:Models, Chemical; D008958:Models, Molecular; D015394:Molecular Structure; D017640:Silicates / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D055672:Static Electricity; D013329:Structure-Activity Relationship
chemical_list: D000538:Aluminum Silicates; D002412:Cations; D006878:Hydroxides; D017633:Magnesium Silicates; D017640:Silicates; C005013:Florisil