The most common and most likely answer to this crossword clue is the 5 letter word KRONA
I've seen this crossword clue in The Daily Telegraph
K
R
O
N
A
Buddy explains!
The straight part
We know that "Capital of Sweden?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case capital of sweden? = krona.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does KRONA mean?
KRONA noun- The official currency of Sweden.