ab initio

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Ab Initio

[Latin, From the beginning; from the first act; from the inception.] An agreement is said to be "void ab initio" if it has at no time had any legal validity. A party may be said to be a trespasser, an estate said to be good, an agreement or deed said to be void, or a marriage or act said to be unlawful, ab initio. Contrasted in this sense with ex post facto, or with postea.

The illegality of the conduct or the revelation of the real facts makes the entire situation illegal ab initio (from the beginning), not just from the time the wrongful behavior occurs. A person who enters property under the authority of law but who then by misconduct abuses his or her right to be on the property is considered a trespasser ab initio. If a sheriff enters property under the authority of a court order requiring him to seize a valuable painting, but instead he takes an expensive marble sculpture, he would be a trespasser from the beginning. Since the officer abused his authority, a court would presume that he intended from the outset to use that authority as a cloak from under which to enter the property for a wrongful purpose. This theory, used to correct abuses by public officers, has largely fallen into disuse.

West's Encyclopedia of American Law, edition 2. Copyright 2008 The Gale Group, Inc. All rights reserved.

ab initio

prep. lawyer Latin for "from the start," as "it was legal ab initio."

Copyright © 1981-2005 by Gerald N. Hill and Kathleen T. Hill. All Right reserved.

ab initio

‘from the beginning’.
Collins Dictionary of Law © W.J. Stewart, 2006

AB INITIO, from the beginning.
     2. When a man enters upon lands or into the house of another by authority of law, and afterwards abuses that authority, he becomes a trespasser ab initio. Bac. Ab. Trespass, B.; 8 Coke, 146 2 Bl. Rep. 1218 Clayt. 44. And if an officer neglect to remove goods attached within a reasonable time and continue in possession, his entry becomes a trespass ab initio. 2 Bl. Rep. 1218. See also as to other cases, 2 Stra. 717 1 H. Bl. 13 11 East, 395 2 Camp. 115, 2 Johns. 191; 10 Johns. 253; ibid. 369.
     3. But in case of an authority in fact, to enter, an abuse of such authority will not, in general, subject the party to an action of trespass, Lane, 90 ; Bae. Ab. Trespass, B ; 2 T. It. 166. See generally 1 Chit. Pl. 146. 169. 180.

A Law Dictionary, Adapted to the Constitution and Laws of the United States. By John Bouvier. Published 1856.
References in periodicals archive ?
These conclusions were consistent with our previous ab initio calculations, which also indicated that Oz:G is more stable than Oz:A.
[.sup.4]He thermophysical properties: new ab initio calculations, J.
The ab initio method involves a more fundamental approach to solving the Schrodinger equation than does the semiempirical method, although there are some assumptions implicit in such calculations (16), The basic approximation of ab initio calculation is that the total wave function is a single Slater determinant and the resultant expression of the molecular orbitals is a linear combination of atomic orbital basis functions (LCAO): in other word, ab initio calculation can be initiated once a basis for the LCAO is chosen.
The electronic structure of those compounds has been investigated also by ab initio calculations. Due to the possible multireference character of these highly conjugated systems, static correlation is taken into account using Complete Active Space Self Consistent Field (CAS-SCF) level of theory, and effects of dynamic correlation are included using multireference second-order perturbation theory and in particular N-Electron Valence Perturbation Theory (NEVPT2) method.
In this direction, in order to gain insight into neoteric material, a nano quaternary ammonium haloaluminate complex was synthesized by using an equal molar ratio of a quaternary ammonium salt and aluminum chloride compounds and then was identified by different experimental methods and finally was determined stable configuration of complex via an ab initio calculations.
These measurements are compared to the results of ab initio calculations carried out using 6-31+G(d) Gaussian basis set for a restricted Hartree-Fock computation.
Our measurements of both K[[alpha].sub.1,2] and K[[beta].sub.1,3] diagram spectra to be described below [13-15], carried out in conjunction with relativistic multiconfigurational Dirac-Fock (RMCDF) ab initio calculations, also supports this interpretation, and provide accurate numerical estimate of the magnitude of the contribution from these effects to the lineshape.
In addition, the potential energy surface features are compared to recently reported Ab Initio calculations for similar systems.
The three core courses are Quantum Chemistry and Methods of Computational Chemistry, which give the theoretical background, and Computational Chemistry Methods Laboratory, which gives a deeper analysis of the computational methods in use, such as molecular mechanics, semiempirical and ab initio calculations, and density functional theory.
Yakobson, "Probing properties of boron a-tubes by ab initio calculations," Nano Letters, vol.