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Can someone explain wiberg bond indices and compare this bond...
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Justin Credible
Can someone explain wiberg bond indices and compare this bond...
As stated by Tian Lu's answer to your question, Wiberg bond order is for orthogonal orbitals. Mulliken population analysis has no physical or mathematical limits as the basis set is improved towards completeness, so you should definitely avoid it. Mayer bond order is a generalization to non-orthogonal orbitals.
However, a recent paper has shown that Mayer bond order is sensitive to the eigenvalues of the density matrix and thus can yield vastly different results for DFT versus coupled-cluster and configuration interaction calculations: T. A. Manz, "Introducing DDEC6 atomic population analysis: part 3. Comprehensive method to compute bond orders," RSC Advances, 7 (2017) 45552-45581 (http://dx.doi.org/10.1039/C7RA07400J ). This paper introduces a new method for computing bond orders that is more general and more robust. The method is implemented in the free Chargemol program (http://ddec.sourceforge.net) and can analyze outputs from GAUSSIAN, VASP, and other quantum chemistry programs.
As stated by Tian Lu's answer to your question, Wiberg bond order is for orthogonal orbitals. Mulliken population analysis has no physical or mathematical limits as the basis set is improved towards completeness, so you should definitely avoid it. Mayer bond order is a generalization to non-orthogonal orbitals.
However, a recent paper has shown that Mayer bond order is sensitive to the eigenvalues of the density matrix and thus can yield vastly different results for DFT versus coupled-cluster and configuration interaction calculations: T. A. Manz, "Introducing DDEC6 atomic population analysis: part 3. Comprehensive method to compute bond orders," RSC Advances, 7 (2017) 45552-45581 (http://dx.doi.org/10.1039/C7RA07400J ). This paper introduces a new method for computing bond orders that is more general and more robust. The method is implemented in the free Chargemol program (http://ddec.sourceforge.net) and can analyze outputs from GAUSSIAN, VASP, and other quantum chemistry programs.
There is no such Mulliken bond order definition. However, some pi bond order definitions, like Mayer BO, are based on the Mulliken population scheme. On the other hand, Wiberg bond index is a sum of bond orders between two orbitals. Each bond order here represents the difference between two times of the electronic density and its square (2q - q^2). This method has some restrictions and limitations, so Mayer and many others tried to generalize it. Thanks!
There is no such Mulliken bond order definition. However, some pi bond order definitions, like Mayer BO, are based on the Mulliken population scheme. On the other hand, Wiberg bond index is a sum of bond orders between two orbitals. Each bond order here represents the difference between two times of the electronic density and its square (2q - q^2). This method has some restrictions and limitations, so Mayer and many others tried to generalize it. Thanks!
Restrictly speaking, Mulliken bond order is not a bond order definition but a measure of overlap population between two atoms. Mulliken bond order does not correlate well with either bonding strength or bond multilicity, and its magnitude differs from formal bond order significantly.
Wiberg was originally defined for close-shell semi-empirical wavefunctions in 1968. For typical chemical bonds, its value is usually very close to formal bond order. The main limitation of Wiberg bond order is that orthonormal condition of basis functions is assumed, however, the basis functions used in modern ab-initio calculation is obviously not an orthonormal set, that means Wiberg is not directly applicable to ab-initio wavefunctions.
Though the starting point is different, the Mayer bond order proposed in 1983 may be viewed as a generalization of Wiberg bond order for ab-initio cases, since the overlap matrix is taken into account. In addition, open-shell form of Mayer bond order is explicitly given. The property of Mayer bond order is commonly similar to Wiberg bond order.
Note that if the basis functions used in ab-initio calculations are orthogonalized in some manners first, for example by Lowdin orthogonalization or the OWSO orthogonalization used in NBO analysis, the Wiberg can also be calculated, and the result will be strongly depend on the orthogonalization method employed.
More discussions in this topic can be found in Section 3.11 of manual of Multiwfn program (multiwfn.codeplex.com), JCC,28,204 and Journal of Molecular Structure: THEOCHEM 870 (2008) 1–9.
Restrictly speaking, Mulliken bond order is not a bond order definition but a measure of overlap population between two atoms. Mulliken bond order does not correlate well with either bonding strength or bond multilicity, and its magnitude differs from formal bond order significantly.
Wiberg was originally defined for close-shell semi-empirical wavefunctions in 1968. For typical chemical bonds, its value is usually very close to formal bond order. The main limitation of Wiberg bond order is that orthonormal condition of basis functions is assumed, however, the basis functions used in modern ab-initio calculation is obviously not an orthonormal set, that means Wiberg is not directly applicable to ab-initio wavefunctions.
Though the starting point is different, the Mayer bond order proposed in 1983 may be viewed as a generalization of Wiberg bond order for ab-initio cases, since the overlap matrix is taken into account. In addition, open-shell form of Mayer bond order is explicitly given. The property of Mayer bond order is commonly similar to Wiberg bond order.
Note that if the basis functions used in ab-initio calculations are orthogonalized in some manners first, for example by Lowdin orthogonalization or the OWSO orthogonalization used in NBO analysis, the Wiberg can also be calculated, and the result will be strongly depend on the orthogonalization method employed.
More discussions in this topic can be found in Section 3.11 of manual of Multiwfn program (multiwfn.codeplex.com), JCC,28,204 and Journal of Molecular Structure: THEOCHEM 870 (2008) 1–9.
i want to study electrophil subsitution of toluene and the regioselectivity . i use local fukui indice ? for the charge and multiplicity i use the neutre and the charge forme ( 0 1 and +1 2 ).
i want to study electrophil subsitution of toluene and the regioselectivity . i use local fukui indice ? for the charge and multiplicity i use the neutre and the charge forme ( 0 1 and +1 2 ).
Restrictly speaking, Mulliken bond order is not a bond order definition but a measure of overlap population between two atoms. Mulliken bond order does not correlate well with either bonding strength or bond multilicity, and its magnitude differs from formal bond order significantly.
Wiberg was originally defined for close-shell semi-empirical wavefunctions in 1968. For typical chemical bonds, its value is usually very close to formal bond order. The main limitation of Wiberg bond order is that orthonormal condition of basis functions is assumed, however, the basis functions used in modern ab-initio calculation is obviously not an orthonormal set, that means Wiberg is not directly applicable to ab-initio wavefunctions.
Though the starting point is different, the Mayer bond order proposed in 1983 may be viewed as a generalization of Wiberg bond order for ab-initio cases, since the overlap matrix is taken into account. In addition, open-shell form of Mayer bond order is explicitly given. The property of Mayer bond order is commonly similar to Wiberg bond order.
Note that if the basis functions used in ab-initio calculations are orthogonalized in some manners first, for example by Lowdin orthogonalization or the OWSO orthogonalization used in NBO analysis, the Wiberg can also be calculated, and the result will be strongly depend on the orthogonalization method employed.
More discussions in this topic can be found in Section 3.11 of manual of Multiwfn program (multiwfn.codeplex.com), JCC,28,204 and Journal of Molecular Structure: THEOCHEM 870 (2008) 1–9.
Restrictly speaking, Mulliken bond order is not a bond order definition but a measure of overlap population between two atoms. Mulliken bond order does not correlate well with either bonding strength or bond multilicity, and its magnitude differs from formal bond order significantly.
Wiberg was originally defined for close-shell semi-empirical wavefunctions in 1968. For typical chemical bonds, its value is usually very close to formal bond order. The main limitation of Wiberg bond order is that orthonormal condition of basis functions is assumed, however, the basis functions used in modern ab-initio calculation is obviously not an orthonormal set, that means Wiberg is not directly applicable to ab-initio wavefunctions.
Though the starting point is different, the Mayer bond order proposed in 1983 may be viewed as a generalization of Wiberg bond order for ab-initio cases, since the overlap matrix is taken into account. In addition, open-shell form of Mayer bond order is explicitly given. The property of Mayer bond order is commonly similar to Wiberg bond order.
Note that if the basis functions used in ab-initio calculations are orthogonalized in some manners first, for example by Lowdin orthogonalization or the OWSO orthogonalization used in NBO analysis, the Wiberg can also be calculated, and the result will be strongly depend on the orthogonalization method employed.
More discussions in this topic can be found in Section 3.11 of manual of Multiwfn program (multiwfn.codeplex.com), JCC,28,204 and Journal of Molecular Structure: THEOCHEM 870 (2008) 1–9.
As stated by Tian Lu's answer to your question, Wiberg bond order is for orthogonal orbitals. Mulliken population analysis has no physical or mathematical limits as the basis set is improved towards completeness, so you should definitely avoid it. Mayer bond order is a generalization to non-orthogonal orbitals.
However, a recent paper has shown that Mayer bond order is sensitive to the eigenvalues of the density matrix and thus can yield vastly different results for DFT versus coupled-cluster and configuration interaction calculations: T. A. Manz, "Introducing DDEC6 atomic population analysis: part 3. Comprehensive method to compute bond orders," RSC Advances, 7 (2017) 45552-45581 (http://dx.doi.org/10.1039/C7RA07400J ). This paper introduces a new method for computing bond orders that is more general and more robust. The method is implemented in the free Chargemol program (http://ddec.sourceforge.net) and can analyze outputs from GAUSSIAN, VASP, and other quantum chemistry programs.
As stated by Tian Lu's answer to your question, Wiberg bond order is for orthogonal orbitals. Mulliken population analysis has no physical or mathematical limits as the basis set is improved towards completeness, so you should definitely avoid it. Mayer bond order is a generalization to non-orthogonal orbitals.
However, a recent paper has shown that Mayer bond order is sensitive to the eigenvalues of the density matrix and thus can yield vastly different results for DFT versus coupled-cluster and configuration interaction calculations: T. A. Manz, "Introducing DDEC6 atomic population analysis: part 3. Comprehensive method to compute bond orders," RSC Advances, 7 (2017) 45552-45581 (http://dx.doi.org/10.1039/C7RA07400J ). This paper introduces a new method for computing bond orders that is more general and more robust. The method is implemented in the free Chargemol program (http://ddec.sourceforge.net) and can analyze outputs from GAUSSIAN, VASP, and other quantum chemistry programs.
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There is no such Mulliken bond order definition.
However, some pi bond order definitions, like Mayer BO, are based on the Mulliken population scheme.
On the other hand, Wiberg bond index is a sum of bond orders between two orbitals.
Each bond order here represents the difference between two times of the electronic density and its square (2q - q^2). This method has some restrictions and limitations, so Mayer and many others tried to generalize it.
Thanks!
There is no such Mulliken bond order definition.
However, some pi bond order definitions, like Mayer BO, are based on the Mulliken population scheme.
On the other hand, Wiberg bond index is a sum of bond orders between two orbitals.
Each bond order here represents the difference between two times of the electronic density and its square (2q - q^2). This method has some restrictions and limitations, so Mayer and many others tried to generalize it.
Thanks!
More
VOTE
Restrictly speaking, Mulliken bond order is not a bond order definition but a measure of overlap population between two atoms. Mulliken bond order does not correlate well with either bonding strength or bond multilicity, and its magnitude differs from formal bond order significantly.
Wiberg was originally defined for close-shell semi-empirical wavefunctions in 1968. For typical chemical bonds, its value is usually very close to formal bond order. The main limitation of Wiberg bond order is that orthonormal condition of basis functions is assumed, however, the basis functions used in modern ab-initio calculation is obviously not an orthonormal set, that means Wiberg is not directly applicable to ab-initio wavefunctions.
Though the starting point is different, the Mayer bond order proposed in 1983 may be viewed as a generalization of Wiberg bond order for ab-initio cases, since the overlap matrix is taken into account. In addition, open-shell form of Mayer bond order is explicitly given. The property of Mayer bond order is commonly similar to Wiberg bond order.
Note that if the basis functions used in ab-initio calculations are orthogonalized in some manners first, for example by Lowdin orthogonalization or the OWSO orthogonalization used in NBO analysis, the Wiberg can also be calculated, and the result will be strongly depend on the orthogonalization method employed.
More discussions in this topic can be found in Section 3.11 of manual of Multiwfn program (multiwfn.codeplex.com), JCC,28,204 and Journal of Molecular Structure: THEOCHEM 870 (2008) 1–9.
Restrictly speaking, Mulliken bond order is not a bond order definition but a measure of overlap population between two atoms. Mulliken bond order does not correlate well with either bonding strength or bond multilicity, and its magnitude differs from formal bond order significantly.
Wiberg was originally defined for close-shell semi-empirical wavefunctions in 1968. For typical chemical bonds, its value is usually very close to formal bond order. The main limitation of Wiberg bond order is that orthonormal condition of basis functions is assumed, however, the basis functions used in modern ab-initio calculation is obviously not an orthonormal set, that means Wiberg is not directly applicable to ab-initio wavefunctions.
Though the starting point is different, the Mayer bond order proposed in 1983 may be viewed as a generalization of Wiberg bond order for ab-initio cases, since the overlap matrix is taken into account. In addition, open-shell form of Mayer bond order is explicitly given. The property of Mayer bond order is commonly similar to Wiberg bond order.
Note that if the basis functions used in ab-initio calculations are orthogonalized in some manners first, for example by Lowdin orthogonalization or the OWSO orthogonalization used in NBO analysis, the Wiberg can also be calculated, and the result will be strongly depend on the orthogonalization method employed.
More discussions in this topic can be found in Section 3.11 of manual of Multiwfn program (multiwfn.codeplex.com), JCC,28,204 and Journal of Molecular Structure: THEOCHEM 870 (2008) 1–9.
More
VOTE
i want to study electrophil subsitution of toluene and the regioselectivity . i use local fukui indice ? for the charge and multiplicity i use the neutre and the charge forme ( 0 1 and +1 2 ).
i want to study electrophil subsitution of toluene and the regioselectivity . i use local fukui indice ? for the charge and multiplicity i use the neutre and the charge forme ( 0 1 and +1 2 ).
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VOTE
Thanks for your guidance
Thanks for your guidance
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Restrictly speaking, Mulliken bond order is not a bond order definition but a measure of overlap population between two atoms. Mulliken bond order does not correlate well with either bonding strength or bond multilicity, and its magnitude differs from formal bond order significantly.
Wiberg was originally defined for close-shell semi-empirical wavefunctions in 1968. For typical chemical bonds, its value is usually very close to formal bond order. The main limitation of Wiberg bond order is that orthonormal condition of basis functions is assumed, however, the basis functions used in modern ab-initio calculation is obviously not an orthonormal set, that means Wiberg is not directly applicable to ab-initio wavefunctions.
Though the starting point is different, the Mayer bond order proposed in 1983 may be viewed as a generalization of Wiberg bond order for ab-initio cases, since the overlap matrix is taken into account. In addition, open-shell form of Mayer bond order is explicitly given. The property of Mayer bond order is commonly similar to Wiberg bond order.
Note that if the basis functions used in ab-initio calculations are orthogonalized in some manners first, for example by Lowdin orthogonalization or the OWSO orthogonalization used in NBO analysis, the Wiberg can also be calculated, and the result will be strongly depend on the orthogonalization method employed.
More discussions in this topic can be found in Section 3.11 of manual of Multiwfn program (multiwfn.codeplex.com), JCC,28,204 and Journal of Molecular Structure: THEOCHEM 870 (2008) 1–9.
Restrictly speaking, Mulliken bond order is not a bond order definition but a measure of overlap population between two atoms. Mulliken bond order does not correlate well with either bonding strength or bond multilicity, and its magnitude differs from formal bond order significantly.
Wiberg was originally defined for close-shell semi-empirical wavefunctions in 1968. For typical chemical bonds, its value is usually very close to formal bond order. The main limitation of Wiberg bond order is that orthonormal condition of basis functions is assumed, however, the basis functions used in modern ab-initio calculation is obviously not an orthonormal set, that means Wiberg is not directly applicable to ab-initio wavefunctions.
Though the starting point is different, the Mayer bond order proposed in 1983 may be viewed as a generalization of Wiberg bond order for ab-initio cases, since the overlap matrix is taken into account. In addition, open-shell form of Mayer bond order is explicitly given. The property of Mayer bond order is commonly similar to Wiberg bond order.
Note that if the basis functions used in ab-initio calculations are orthogonalized in some manners first, for example by Lowdin orthogonalization or the OWSO orthogonalization used in NBO analysis, the Wiberg can also be calculated, and the result will be strongly depend on the orthogonalization method employed.
More discussions in this topic can be found in Section 3.11 of manual of Multiwfn program (multiwfn.codeplex.com), JCC,28,204 and Journal of Molecular Structure: THEOCHEM 870 (2008) 1–9.
More
VOTE