Now showing items 1-20 of 21

    • Ab Initio Molecular Dynamics Simulations of Ti-2 on C-20 Collisions and C20Ti2 Configurations 

      Muñoz, Francisco; Cárdenas Valencia, Carlos; José, Rogan; Valdivia Hepp, Juan; Fuentealba Rosas, Patricio; Kiwi Tichauer, Miguel (ACS Publications, 2013-02-28)
      The dynamics of the collision process of a titanium dimer against a C-20 nanocluster in the bowl configuration is simulated by means ab initio molecular dynamics, focusing our interest on the first steps to synthesize ...
    • An explicit approach to conceptual density functional theory descriptors of arbitrary order 

      Heidar Zadeh, Farnaz; Richer, Michael; Fias, Stijn; Miranda Quintana, Ramón; Chan, Matthew; Franco Pérez, Marco; González Espinoza, Cristina; Kim, Taewon; Lanssens, Caitlin; Patel, Anand; Yang, Xiaotian; Vöhringer Martinez, Esteban; Cárdenas Valencia, Carlos; Verstraelen, Toon; Ayers, Paul W. (Elsevier, 2016)
      We present explicit formulas for arbitrary-order derivatives of the energy, grand potential, electron density, and higher-order response functions with respect to the number of electrons, and the chemical potential for any ...
    • Atomic Charges and the Electrostatic Potential Are Ill-Defined in Degenerate Ground States 

      Bultinck, Patrick; Cárdenas Valencia, Carlos; Fuentealba Rosas, Patricio; Johnson, Paul A.; Ayers, Paul W. (American Chemical Society, 2013)
      A system in a spatially degenerate ground state responds in a qualitatively different way to positive and negative point charges. This means that the molecular electrostatic potential is ill-defined for degenerate ...
    • Condensation of the highest occupied molecular orbital within the electron localization function domains 

      Chamorro, Eduardo; Duque, M.; Cárdenas Valencia, Carlos; Santos, J. C.; Tiznado Vásquez, William; Fuentealba Rosas, Patricio (INDIAN ACADEMY SCIENCES, 2005-09)
      Use of regions of space defined by topological analysis of electron localization function (ELF) as reactivity descriptors is explored. By starting from the fact that the ELF presents high values in the regions where it is ...
    • How predictive could alchemical derivatives be? 

      Muñoz, Macarena; Cárdenas Valencia, Carlos (Royal Society Chemistry, 2017)
      The chemical space contains all possible compounds that can be imagined. Its size easily equals the number of fundamental particles in the observable universe. Rational design of compounds aims to find those sectors of the ...
    • How to Compute the Fukui Matrix and Function for Systems with (Quasi-)Degenerate States 

      Bultinck, Patrick; Cárdenas Valencia, Carlos; Fuentealba Rosas, Patricio; Johnson, Paul A.; Ayers, Paul W. (American Chemical Society, 2014)
      A system in a spatially (quasi-)degenerate ground state responds in a qualitatively different way to a change in the external potential. Consequently, the usual method for computing the Fukui function, namely, taking ...
    • How to Compute the Fukui Matrix and Function for Systems with (Quasi-)Degenerate States 

      Bultinck, Patrick; Cárdenas Valencia, Carlos; Fuentealba Rosas, Patricio; Johnson, Paul A.; Ayers, Paul W. (ACS, 2013)
      A system in a spatially (quasi-)degenerate ground state responds in a qualitatively different way to a change in the external potential. Consequently, the usual method for computing the Fukui function, namely, taking ...
    • In pursuit of negative Fukui functions: examples where the highest occupied molecular orbital fails to dominate the chemical reactivity 

      Echegaray, Eleonora; Cárdenas Valencia, Carlos; Rabi, Sandra; Rabi, Nataly; Lee, Sungmin; Zadeh, Farnaz Heidar; Toro Labbe, Alejandro; Anderson, James S.; Ayers, Paul W. (Springer, 2013)
      In our quest to explore molecules with chemically significant regions where the Fukui function is negative, we explored reactions where the frontier orbital that indicates the sites for electrophilic attack is not the ...
    • Mechanism of fluorophore quenching in a pre-fluorescent nitroxide probe: A theoretical illustration 

      Aliaga, Carolina; Fuentealba Rosas, Patricio; Caroli Rezende, Marcos; Cárdenas Valencia, Carlos (Elsevier, 2014)
      The mechanism of fluorophore quenching in QT, a pre-fluorescent quinoline-TEMPO probe, is illustrated with the aid of a molecular-orbital analysis, offering a pictorial view of the process that takes place in the excited ...
    • Nuclear reactivity indices in the context of spin polarized density functional theory 

      Cárdenas Valencia, Carlos; Lamsabhi, Al Mokhtar; Fuentealba Rosas, Patricio (ELSEVIER, 2006-03-20)
      In this work, the nuclear reactivity indices of density functional theory have been generalized to the spin polarized case and their relationship to electron spin polarized indices has been established. in particular, the ...
    • A numerical study of the Lieb-Thirring kinetic energy lower bound 

      Inostroza, David; Cárdenas Valencia, Carlos; Fuentealba Rosas, Patricio (Taylor and Francis, 2016)
      In this work, the Lieb-Thirring kinetic energy bound is numerically examined for a variety of systems: the hydrogen-like atoms, neutral atoms, isoelectronic series of atomic ions, the Hooke's atom and some small molecules. ...
    • On the exponential model for energy with respect to number of electrons 

      Fuentealba Rosas, Patricio; Cárdenas Valencia, Carlos (Springer, 2013)
      Using an exponential model for the variation in energy with respect to the number of electrons it is shown that, within the model, the hardness, softness, electrophilicity and other global parameters connected to higher ...
    • On understanding the chemical origin of band gaps 

      Contreras García, J.; Cárdenas Valencia, Carlos (Springer, 2017)
      Conceptual DFT and quantum chemical topology provide two different approaches based on the electron density to grasp chemical concepts. We present a model merging both approaches, in order to obtain physical properties ...
    • Proposal of a simple and effective local reactivity descriptor through a topological analysis of an orbital-weighted fukui function 

      Pino Ríos, Ricardo; Yáñez, Osvaldo; Inostroza, Diego; Ruiz, Lina; Cárdenas Valencia, Carlos; Fuentealba Rosas, Patricio; Tiznado, William (Wiley, 2017)
      The prediction of reactivity is one of the long-standing objectives of chemistry, contributing to enforce the link between theory and experiment. In particular, the regioselectivity of aromatic molecules has motivated the ...
    • Quantitative electrophilicity measures 

      González Martínez, Marco; Cárdenas Valencia, Carlos; Rodríguez, Juan, I; Liu, Shubin; Heidar Zadeh, Farnaz; Miranda Quintana, Ramon Alain; Ayers, Paul W. (Peking University Press, 2018)
      Quantitative correlation of several theoretical electrophilicity measures over different families of organic compounds are examined relative to the experimental values of Mayr et al. Notably, the ability to predict these ...
    • Regional Electrophilic and Nucleophilic Fukui Functions Efficiently Highlight the Lewis Acidic/Basic Regions in Ionic Liquids 

      Cerda Monje, Andrea; Ormazábal Toledo, Rodrigo; Cárdenas Valencia, Carlos; Fuentealba Rosas, Patricio; Contreras Ramos, Renato (ACS, 2014)
      The origin of catalysis and selectivity induced by room temperature ionic liquids in several organic reactions has putatively been associated with the concept of cation ef fect (hydrogen bond donor ability of the ionic ...
    • The Fukui Potential and the Capacity of Charge and the Global Hardness of Atoms 

      Cárdenas Valencia, Carlos; Tiznado Vásquez, William; Ayers, Paul W.; Fuentealba Rosas, Patricio (AMER CHEMICAL SOC, 2011-02-25)
      In the course of a reaction it is the shape of the Fukui potential that guides a distant reagent toward the site where an electrophile/nucleophile is willing to accept/ donate charge. In this paper we explore the ...
    • The HSAB principle from a finite temperature grand‑canonical perspective 

      Miranda Quintana, Ramón; Kim, Taewon David; Cárdenas Valencia, Carlos; Ayers, Paul W. (Springer, 2017)
      We provide a new proof for Pearson’s hard/ soft acid/base (HSAB) principle. Unlike alternative proofs, we do not presuppose a simplified parabolic dependence on the energy of the system with respect to changes in ...
    • Theoretical study of the surface reactivity of alkaline earth oxides: Local density of states evaluation of the local softness 

      Cárdenas Valencia, Carlos; De Proft, Frank; Chamorro, Eduardo; Fuentealba Rosas, Patricio; Geerlings, Paul (AMER INST PHYSICS, 2008-01-17)
      The local softness of MgO, CaO, SrO, and BaO (100) surfaces has been studied using a model based on the local density of states. In all the species, the local softness chemical reactivity of oxygen atoms at the surface ...
    • Theoretical study on CDK2 inhibitors using a global softness obtained from the density of states 

      Alzate Morales, Jans; Tiznado Vásquez, William; Santos Vargas, Juan; Cárdenas Valencia, Carlos; Contreras Ramos, Renato (2007)
      We report a theoretical study on a series of CDK2 inhibitors using a set of global reactivity indices defined in terms of the density of states. The statistical analysis was performed on the basis of two groups of 11 and ...