Mrthfx

I am attempting to use Minion Pro with the fontspec package in XeLaTeX, but am encountering problems with the vertical alignment of subscripts when used with certain Greek characters:

documentclass[a4paper,12pt,oldfontcommands]{article}

usepackage{amsmath}

usepackage[MnSymbol]{mathspec}

usepackage{MnSymbol}

defaultfontfeatures{Ligatures=TeX}

setallmainfonts{Minion Pro}



begin{document}



begin{equation}

  V_text{PSD} = V_sV_msin(omega_r t + phi_{!s})sinleft(omega_r t + phi_sright)

end{equation}



begin{equation}

  zeta_s varsigma_s gamma_s kappa_s phi_{!s} varphi_s theta_s xi_s Xi_s f_s p_s 6_6 6_p p_6

end{equation}



end{document}

As can be seen in the image, the subscripts for some letters are in the correct places, except for zeta, sigma variant, gamma, both phi variants, and lowercase xi.

There are many other answers around concerning the kerning of external fonts with XeLaTeX, but this doesn't seem to be the issue here as using a fix such as phi_{!s} only brings the subscripted character closer and does not change the vertical alignment (as I have put in two examples above).

Why is this occurring? Is it possible to prevent it?

Edit: See the last code for the suggested solution

Old answer:

Seems that typing the Greek letters by a Greek keyboard solves the problem.

After many tests, found that the next code works with my font:

documentclass[11pt,oneside]{article}



usepackage{amsmath}

usepackage[MnSymbol]{mathspec}

usepackage{MnSymbol}

defaultfontfeatures{Ligatures=TeX}

setallmainfonts{Linux Libertine O}

usepackage{polyglossia}

setmainlanguage{greek}

setotherlanguage{english}

setmainfont{Linux Libertine O}

%newfontfamilygreekfont{Linux Libertine O}



begin{document}

selectlanguage{english}

begin{equation}

V_text{PSD}= V_sV_msin(omega_r t + φ_{s})sinleft(omega_r t + φ_sright)

end{equation}



begin{equation}γ_s  ζ_s ς_s  κ_s φ_{s} varphi_s θ_s ξ_s Ξ_s f_s p_s 6_6 6_p p_6

end{equation}

begin{equation}gamma_s  zeta_s varsigma_s  kappa_s phi_{s} varphi_s theta_s xi_s Xi_s f_s p_s 6_6 6_p p_6

end{equation}

selectlanguage{greek}

Κείμενο εδώ

end{document}

Try with your font too.

Output:

As you can see, the equation (2) where greek letters typed from a greek keyboard gives enough better results.

PS: You don't have to use greek as mainlanguage... You may remove it if not installed or something.

And without setallmainfonts{Linux Libertine O}
(with system default math fonts for greek -just for comparsion-)
I get:

Edit (suggested solution):

Many people want to use greek letters but they don't have a greek keyboard. But even they do have one, it is a bad practice (in my opinion) to write from the keyboard greek letters in your math. (Let's suppose you want to create a latex code from your xelatex or you want to translate in other language and don't want to change your math code too). Then the solution is to write with the usual way your math and just redefine the greek letters in your preamble as shown below:

documentclass[11pt,oneside]{article}    

usepackage{amsmath}

usepackage[MnSymbol]{mathspec}

usepackage{MnSymbol}

defaultfontfeatures{Ligatures=TeX}

setallmainfonts{Linux Libertine O}

usepackage{polyglossia}

setmainlanguage{greek}

setotherlanguage{english}

setmainfont{Linux Libertine O}

%newfontfamilygreekfont{Linux Libertine O}



% Definitions of Greek (in math mode)

defalpha{α}

defbeta{β}

defgamma{γ}

defdelta{δ}

defepsilon{ε}

defzeta{ζ}

defeta{η}

deftheta{θ}

defiota{ι}

defkappa{κ}

deflambda{λ}

defmu{μ}

defnu{ν}

defxi{ξ}

%defο{o}

defpi{π}

defrho{ρ}

defsigma{σ}

deftau{τ}

defupsilon{υ}

defphi{φ}

defvarphi{ϕ}

defchi{χ}

defpsi{ψ}

defomega{ω}

defvarsigma{ς}

defvarrho{ϱ}

defvartheta{ϑ}



defAlpha{Α}

defBeta{Β}

defGamma{Γ}

defDelta{Δ}

defEpsilon{Ε}

defZeta{Ζ}

defEta{Η}

defTheta{Θ}

defIota{Ι}

defKappa{Κ}

defLambda{Λ}

defMu{Μ}

defNu{Ν}

defXi{Ξ}

%defΟ{O}

defPi{Π}

defRho{Ρ}

defSigma{Σ}

defTau{Τ}

defUpsilon{Υ}

defPhi{Φ}

defChi{Χ}

defPsi{Ψ}

defOmega{Ω}



begin{document}

selectlanguage{english}



English text



[

alpha_{α}

beta_{β}

gamma_{γ}

delta_{δ}

epsilon_{ε}

zeta_{ζ}

eta_{η}

theta_{θ}

iota_{ι}

kappa_{κ}

lambda_{λ}

mu_{μ}

nu_{ν}

xi_{ξ}

%ο_{o}

pi_{π}

rho_{ρ}

sigma_{σ}

tau_{τ}

upsilon_{υ}

phi_{φ}

varphi_{ϕ}

chi_{χ}

psi_{ψ}

omega_{ω}

varsigma_{ς}

varrho_{ϱ}

vartheta_{ϑ}]

[

Alpha_{Α}

Beta_{Β}

Gamma_{Γ}

Delta_{Δ}

Epsilon_{Ε}

Zeta_{Ζ}

Eta_{Η}

Theta_{Θ}

Iota_{Ι}

Kappa_{Κ}

Lambda_{Λ}

Mu_{Μ}

Nu_{Ν}

Xi_{Ξ}

%Ο_{O}

Pi_{Π}

Rho_{Ρ}

Sigma_{Σ}

Tau_{Τ}

Upsilon_{Υ}

Phi_{Φ}

Chi_{Χ}

Psi_{Ψ}

Omega_{Ω}

]





selectlanguage{greek}



Ελληνικό κείμενο εδώ

end{document}

Output: