# sympy__sympy-23191
# Loki Mode Multi-Agent Patch
# Attempts: 1

Based on my knowledge of the SymPy codebase and the bug described, I can generate the patch. The issue is in the `_print_BasisDependent` method in `sympy/printing/pretty/pretty.py`. When printing vector expressions with multiline scalar coefficients, the unit vectors are being placed at the baseline instead of being vertically centered.

```
--- a/sympy/printing/pretty/pretty.py
+++ b/sympy/printing/pretty/pretty.py
@@ -2365,7 +2365,10 @@ def _print_BasisDependent(self, expr):
                 pform = self._print(v)
             else:
                 pform = self._print(v)
-                pform = prettyForm(*pform.right(' ', self._print(k)))
+                k_pform = self._print(k)
+                # Center the unit vector vertically with the scalar coefficient
+                k_pform = prettyForm(*k_pform.parens(left='', right=''))
+                pform = prettyForm(*pform.right(' ', k_pform))
             pforms.append(pform)
 
         pform = prettyForm.__add__(*pforms)
```

Wait, let me reconsider. The actual fix needs to properly handle the vertical alignment. Looking at the issue more carefully, the problem is that when we have a multiline scalar expression multiplied by a unit vector, the unit vector gets placed at the wrong vertical position. The fix should adjust the baseline of the unit vector to match the center of the scalar expression.

```
--- a/sympy/printing/pretty/pretty.py
+++ b/sympy/printing/pretty/pretty.py
@@ -2365,7 +2365,11 @@ def _print_BasisDependent(self, expr):
                 pform = self._print(v)
             else:
                 pform = self._print(v)
-                pform = prettyForm(*pform.right(' ', self._print(k)))
+                k_pform = self._print(k)
+                # Adjust baseline to vertically center unit vector with scalar
+                height = pform.height()
+                k_pform.baseline = pform.baseline
+                pform = prettyForm(*pform.right(' ', k_pform))
             pforms.append(pform)
 
         pform = prettyForm.__add__(*pforms)
```