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Introduction

    

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Hi! My name is Freddy Fernandes Guimarães. I was born in Belo Horizonte, MG, Brazil, in February 3rd of 1975. I am married and I have two children. My wife's name is Andrezza Saldanha de Oliveira Guimarães, the names of our daughter and son are Laira and Arthur. The football team that I support in Brazil is Clube Atletico Mineiro (nickname: GALO), which was the first Brazilian champion in 1971.

I am a chemist. I graduated in chemistry at the University Federal of Minas Gerais (UFMG) in the year of 2000. My under-graduate final work was in molecular and atomic scattering studies. In the year of 2002, also in the UFMG, I got a Master degree in Physical-Chemistry, studying the conformation of molecular and metallic atomic clusters. This studies were based in the genetic algorithms evolutionary approach, that is an Artificial Intelligence technique, which is applied in the search of the Global Minimum in the potential energy surface.

Nowadays, I am a PhD student at the Theoretical Chemistry, KTH and at the Department of Chemistry at the UFMG. I am studying the two color pump-probe spectroscopy. Basically, my studies are related with the transition of a virtual vibrational state to a core exited or ionized electronic state.  The virtual vibrational state is prepared with a Infrared laser in the electronic ground state. And, it is probed afterwords with x-ray pulse given the absorption probability transition (Fig. 1).  More details in Projects.

Scientific interests


  1. Quantum dynamics:

    1. X-ray photon-ionization.

    2. X-ray photon-excitation.

    3. Pump-probe experiments:

      1. Infrared + X-ray.

      2. Infrared + Infrared.
WP propagation
MOV. 1: Wave Packet propagation in the groud electronic state. The WP is a coherent superpossition of the vibrational states, which is generate by the pump field.
            





                  pump-probe
FIG. 1: Qualitative illustration of pump-probe spectroscopy. The pump infrared laser prepare a virtual vibrational state which is probe by a x-ray field. The spectral shape can be modified for short pulses of the probe signal, which selects the wave packet in a certain region of the PES. The  spectra b and c  represent the absorption probability probed by short x-ray pulse (time and phase dependent spectra). And, d refers to a spectrum probed by a long x-ray pulse (time and phase independent spectrum).





  1. Clusters:

    1. Alloys and molecular clusters

    2. Genetic algorithms.

    3. Global minimum.

    4. Water clusters global minimum.
  cc
FIG. 3: The structures of the lowest-energy composomers found for 11<x+y<30. The Cu atoms are represented by red and Au atoms by yellow. 



W6 Clusters
FIG. 2: The Global Minimum of (H_2O)_6 clusters computed for different empirical potentials. TIP3P a three site potential, TIP4P and ST2 four site potentials, and TIP5P a five site potential.



cc
FIG. 4: All composomers found for a fixed nuclearity N = 19.
The Cu atoms are represented by red and Au atoms by yellow.
                                                                                      


Intellectual production

Publication in indexed journals
  1. F. F. Guimaraes, J. C. Belchior, R. L. Johnston and C. Roberts, Global optimization analysis of water clusters (H2O)(n) (11 <= n <= 13) through a genetic evolutionary approachJournal of Chemical Physics, 116 (19): 8327-8333 May 15 2002.

  2. R. A. Lordeiro, F. F. Guimaraes, J. C. Belchior and R. L. Johnston,  Determination of main structural compositions of nanoalloy clusters of CuxAuy (x+y <= 30) using a genetic algorithm approach, International Journal of Quantum Chemistry, 95 (2): 112-125 Oct 15 2003.

Programs
  1. MGA (Molecular Genetic Algorithm);
    Description: The MGA program searches for the Global Minimum (GM) in potential energy surfaces;
    Authors: F. F. Guimaraes, J. C. Belchior, C. Roberts and C. Roberts.

  2. eSPec;
    Description: The eSPec program solves the time dependent Schrodinger equation;
    Authors: F. F. Guimaraes, V. C. Felicissimo, V. Kimberg, A. Cesar and F. Gelmukhanov

Monographes
  1. Informática no Ensino de Química; Monograph in teaching training - UFMG - Belo Horizonte - Brazil (1999).

  2. Dinâmica Atômica e Molecular: Clássica; Bachelor Monography - UFMG - Belo Horizonte - Brazil (2000).

  3. Estudo e Análise Teórica de Nano-Clusters: Atômicos e Moleculares; Master thesis - UFMG - Belo Horizonte - Brazil (2002).



Collaborators


Photos

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