diff --git a/var/spack/repos/builtin/packages/lammps/package.py b/var/spack/repos/builtin/packages/lammps/package.py
index 17ad7a620f1..5648ea4f5f4 100644
--- a/var/spack/repos/builtin/packages/lammps/package.py
+++ b/var/spack/repos/builtin/packages/lammps/package.py
@@ -399,8 +399,19 @@ class Lammps(CMakePackage, CudaPackage, ROCmPackage, PythonExtension):
 
     depends_on("cxx", type="build")
 
-    # mdi, scafacos, ml-quip, qmmm require C, but not available in Spack
-    for c_pkg in ("adios", "atc", "awpmd", "ml-pod", "electrode", "kim", "h5md", "tools", "rheo"):
+    # scafacos, ml-quip, qmmm require C, but not available in Spack
+    for c_pkg in (
+        "adios",
+        "atc",
+        "awpmd",
+        "electrode",
+        "h5md",
+        "kim",
+        "mdi",
+        "ml-pod",
+        "rheo",
+        "tools",
+    ):
         depends_on("c", type="build", when=f"+{c_pkg}")
 
     # scafacos, ml-quip require Fortran, but not available in Spack
@@ -496,6 +507,7 @@ def url_for_version(self, version):
         "manifold": {"when": "@20210702:"},
         "manybody": {"default": True},
         "mc": {},
+        "mdi": {"when": "@20210702:"},
         "meam": {"when": "@:20181212,20210702:"},
         "mesont": {"when": "@20210702:"},
         "mgpt": {"when": "@20210702:"},
@@ -583,7 +595,6 @@ def url_for_version(self, version):
         "voronoi": {},
         "vtk": {"when": "@20210702:"},
         "yaff": {"when": "@20210702:"},
-        # "mdi": {"when": "@20210702:"}, no mdi package
         # "ml-quip": {"when": "@20210702:"}, no quip package
         # "scafacos": {"when": "@20210702:"}, no scafacos package
         # "user-quip": {"when": "@20190201:20210527"}, no quip package
@@ -719,6 +730,7 @@ def url_for_version(self, version):
     depends_on("pace", when="+ml-pace", type="build")
     depends_on("py-cython", when="+mliap+python", type="build")
     depends_on("py-cython", when="+ml-iap+python", type="build")
+    depends_on("py-mdi", when="+mdi", type=("build", "run"))
     depends_on("py-pip", when="+python", type="build")
     depends_on("py-wheel", when="+python", type="build")
     depends_on("py-build", when="+python", type="build")
diff --git a/var/spack/repos/builtin/packages/py-mdi/package.py b/var/spack/repos/builtin/packages/py-mdi/package.py
new file mode 100644
index 00000000000..689ce83337c
--- /dev/null
+++ b/var/spack/repos/builtin/packages/py-mdi/package.py
@@ -0,0 +1,29 @@
+# Copyright Spack Project Developers. See COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+from spack.package import *
+
+
+class PyMdi(PythonPackage):
+    """MolSSI Driver Interface (MDI) Library
+
+    The MolSSI Driver Interface (MDI) project provides a standardized API for
+    fast, on-the-fly communication between computational chemistry codes. This
+    greatly simplifies the process of implementing methods that require the
+    cooperation of multiple software packages and enables developers to write a
+    single implementation that works across many different codes.
+    """
+
+    homepage = "https://molssi-mdi.github.io/MDI_Library"
+    git = "https://github.com/MolSSI-MDI/MDI_Library.git"
+
+    maintainers("hjjvandam", "rbberger")
+
+    license("BSD-3-Clause", checked_by="hjjvandam")
+
+    version("1.4.33", tag="v1.4.33", commit="f479f18f8d036bd675ba628365dd5f6f0cff1c21")
+
+    depends_on("py-setuptools@42:", type="build")
+    depends_on("py-packaging", type="build")
+    depends_on("cmake@3.5:", type="build")