ETD system

Electronic theses and dissertations repository

 

Tesi etd-10192003-214820


Thesis type
Tesi di laurea vecchio ordinamento
Author
Bizzarri, Marco
email address
marco78zz@virgilio.it
URN
etd-10192003-214820
Title
Simulazione di trasformazioni di fase e dinamica del 4-pentil-4'-cianobifenile (5CB)con potenziale derivato da calcolo ab-initio
Struttura
SCIENZE MATEMATICHE, FISICHE E NATURALI
Corso di studi
CHIMICA
Commissione
relatore Tani, Alessandro
Parole chiave
  • Nessuna parola chiave trovata
Data inizio appello
19/11/2003;
Consultabilità
parziale
Data di rilascio
19/11/2043
Riassunto analitico
In this work, an intermolecular potential for the interaction between 5CB pairs has been reconstructed from a database of interaction energies of the molecular fragments, calculated <br>from ab-initio methods at MP2 level. This function has been employed in a series of molecular dynamics simulations at various temperatures. The simulation results show the experimental cristalline structure stays kinetically stable throughout the temperature range of experimental cristalline phase. We also found a nematic phase at higher temperature and an isotropic liquid phase at still higher temperature. The various phase have been characterized from a structural<br>( radial distribution functions and conformational<br> distribution function of the chain )and dynamic ( diffusion coefficient ) point of view. In the case of nematic phase we have calculated total <br> and local orientational order parameters to compare to the data obtained from NMR <br>spectroscopy while translational diffusion has been studied for both longitudinal ( i.e. along the director ) and both transverse motions.<br>
File