Using (something very like) the standard symbol font Greek letters to set a bit of classical Greek?

Question

In the context of a logic book, set using LaTeX/pdftex in Computer Modern, I'm using Greek letters from the standard math symbol alphabet as symbols.

But on a few occasions I want to typeset an ancient Greek word. It looks odd to use a different font (as supplied by default by e.g. the Teubner package). But trying to fake it with the symbol font doesn't lead to good results with accents etc.

Question: is there an easy way of setting up a \textgreek command that can handle the accents/breathings etc. nicely, that spaces letters nicely, AND delivers output that uses an italic Greek font with letters the same shape as (or very close to) the standard symbol font?

Answer 1

If you can use LuaLaTeX or XeLaTeX, you can load Computer Modern Unicode Serif. This font has polytonic Greek letters based on Computer Modern and the old cbgreek fonts. In order to get the appropriate shapes for Greek text, instead of math symbols, you select the Script=Greek OpenType feature. The \babelfont command handles this automatically.

\documentclass{article}
\usepackage[paperwidth=11cm]{geometry}
\usepackage[english]{babel}
\usepackage{fontspec}
\usepackage{microtype}

\babelprovide[import]{greek}
\newcommand\textgreek[1]{\foreignlanguage{greek}{#1}}
\newenvironment{greek}%
{\begin{otherlanguage}{greek}}%
{\end{otherlanguage}}

\defaultfontfeatures{Scale = MatchLowercase}

\babelfont{rm}
          [Scale=1.0, Ligatures={Common, TeX}, Language=Default]{Latin Modern Roman}
\babelfont[greek]{rm}
          [Language=Default]{CMU Serif}
\babelfont{sf}
          [Ligatures={Common, TeX}, Language=Default]{Latin Modern Sans}
\babelfont[greek]{sf}
          [Language=Default]{CMU Sans Serif}
\babelfont{tt}
          [Language=Default]{Latin Modern Mono}
\babelfont[greek]{tt}
          [Language=Default]{CMU Typewriter Text}

\begin{document}
\begin{greek}
ἄνδρα μοι ἔννεπε, μοῦσα, πολύτροπον, ὃς μάλα πολλὰ
πλάγχθη, ἐπεὶ Τροίης ἱερὸν πτολίεθρον ἔπερσεν:
\end{greek}
\end{document}

I added more \babelfont cases and options than strictly necessary, in order to suppress some warning messages.

If you actually want letters shaped like \theta and \lambda, just load CMU Serif with Script=Default rather than Script=Greek. By default, lowercase Greek math symbols are slanted and uppercase ones are upright, so you could also throw in a \slshape if you want. You could also use \varphi and \vartheta in math mode to make that more consistent with Greek text.

And a version compatible with PDFLaTeX if you need one. Note that the UTF-8 input encoding has been the default since April 2018. PDFLaTeX will therefore understand Greek, if you load the LGR font encoding.

\documentclass{article}
\usepackage[LGR, T1]{fontenc}
\usepackage[utf8]{inputenc} % The default since 2018
\usepackage[paperwidth=11cm]{geometry}
\usepackage[polutonikogreek, main=english]{babel}
\usepackage{microtype}

\DeclareRobustCommand\textgreek[1]{\foreignlanguage{polutonikogreek}{#1}}
\newenvironment{greek}%
{\begin{otherlanguage}{polutonikogreek}}%
{\end{otherlanguage}}

\begin{document}
\begin{greek}
ἄνδρα μοι ἔννεπε, μοῦσα, πολύτροπον, ὃς μάλα πολλὰ
πλάγχθη, ἐπεὶ Τροίης ἱερὸν πτολίεθρον ἔπερσεν:
\end{greek}
\end{document}

Answer 2

Please try with the below code, note that it works in XELaTeX only:

\documentclass{book}
\usepackage{babyloniannum}
\usepackage[polutonikogreek,english]{babel}
\begin{document}
\newfontfamily\greekfont[Script=Greek, Scale=MatchUppercase, Ligatures=TeX]{Old Standard}
\newcommand{\textgreek}[1]{\bgroup\greekfont\emph{#1}\egroup} % 

\textgreek{Ï€Ïότασις}

\end{document}

Output

Using PDFLaTeX

egreg suggested a better way to get in PDFLaTeX, and the codes are:

\documentclass{book}
\usepackage[greek.polutoniko,english]{babel}

\newenvironment{greek}
  {\begin{otherlanguage*}{greek}}
  {\end{otherlanguage*}}

\begin{document}

\begin{greek}
To~u d`e poso~u t`o m'en >esti diwrism'enon, t`o d`e suneqes.
\end{greek}

\end{document}

Output